Count your blessings if BM pays for half of anything.  Our BM paid zero and DH paid for everything you mention.  Then all 3 kids moved in full time.

We had the other problem. The Spermidiot never payed a Cent.  His parents paid all of his 16+ years of CS obligation to my DW for SS.  Though it was a pittance for 10 years.  We did attempt to get them to pay for half of extracurriculars.  Nope, the Judge gave us clarity that CS, regardless the pittance it may be, is the NCPs entire obligation for supporting their kid.  Unless there are other support elements addressed in the CO.  

Interestingly, even when the Judge who issued the CO is pushed to hold a violating side accountable, they have no obligation to enforce the order that they issued.  In addition to the pittance in CS, the SpermClan was ordered to pay for their half of visitation travel costs (each party was required to bear the cost of transporting the Skid to their location), and half of all medical related expenses not covered by insurance.

They never paid a Cent.  The Judge told us to take them to small claims court if we wanted out money.  Another nail in the coffin of my considering that an insane number of Judges and sadly even lawyers, have to come from the bottom 10% or even lower echelons of the legal "profession". So, to keep legal action open as an option, we bill them twice a year with a long spreadsheet of every bill, a copy of every bill, and added penalties and interest.  

We likely will never take cation.  However, if they ever again get shitty with SS, it will be game on to the tune of $10K+.

They hate when they get the bill.  Though it has been quite a while, SpermGrandHag used to call and whine to DW to let it go, asking why she keeps bringing up the past, how it is not fair that they might have to pay so much money, etc...  Interestingly, is that the bill goes to the Hag and to the Spermidiot.  Hag gets upset about it. Not one peep out of Spermidiot.  The lawsuit, if it happens, will be entirely focused on him. He will cry to mommy and try to get her to pay it.  If we get there, I hope that SpermGrandHag and SpermGrandPa make him hold the outcome entirely without their checkbook. 

I thankfully do not have this problem. DH pays monthly child support exactly to the cent which it is ordered and half of all uninsured medical expenses (again as ordered). He does not pay for any extras.

DH used to pay half of things like sports, school field trips, etc. because BM used to guilt him that "it's what real parents do," incinuating that if DH didn't pay, he wasn't a real parent to SS11.5. In 2019, our attorney scolded DH for paying all the extras, because BM was literally using sports and extracurriculars to overschedule SS and interfere with DH's ability to get additional long distance visitation. BM told the judge that because SS was so busy with sports, he couldn't visit more, and it wasn't fair to SS to miss out on his sports and the judge agreed.

So, DH told BM that he would continue to pay for half of sports/extracurriculars only if they made the agreement that all sports had to be agreed upon and discussed beforehand and if they could not agree, SS would not be enrolled or BM would have to eat the entire cost. DH was hoping it would force BM to enroll in a reasonable number of sports/extracurriculars. BM didn't want to give up control or have to consult DH on anything, so she lost DH's half of payment. SS is 11.5 and is enrolled in 4 or 5 sports per year plus private tutoring for a foreign language, plus advanced placement math classes. BM continues to add more and more overlapping extracurriculars whenever SS shows even the slightest interest in something. SS is a burned out kid who acts like school and sports are his full time job and he hasn't had a break in 5 years. We feel bad for SS but at least we aren't financially contributing to that shit show anymore. 

We are currently paying for a portion of SS' braces which was ordered by the court. We have 16 more months of payments and should be done by Mayish of 2025. 

Yes!

My ex Disneyland dad was so gullible and willfully obtuse that he had the audacity to not only pay his beastly breeder regularly for child support but he also drove all over the city at his failed former families last minute random beck n call remote errand bitch pinging service(waste of time + gas money) during HER parenting times, paid health insurance, remote pinging devices/remote pinging devices monthly service plans/, morning and afternoon school carpools during HER parenting times, dentist and doctor appointment during HER parenting times and more....

Then felt "guilty" because the breeder had them during the week. Like "you dumb fool that's what that c*nt is supposed to do and with you running all over town (during her parenting times) like a chicken with its head cut off ... your dumb ass is probably paying her while you do way more than 50% of the load which is NOT what you agreed to in that parenting plan" 

To top it off this idiot erroneously thought that I was going to let his breeder drop her loud/messy/disrespectful kids off at my peaceful home (the woman she didn't want her ferals around) every Friday night immediately after I got off work while she had her kid-free weekend started early in Fridays and while he worked overtime but didn't bring any of that overtime money into our household 

I told him NO I will not be responsible for your kids while you work + overtime every Friday night....you better DEMAND that exwife take care of those kids until you get off work like you're paying her child support money to do!

You better get ALL your child support moneys worth out of that beastly breeder ... or else!!!!

I know your situation is somewhat extreme with the amount of time and money he throws at his kids EC activities. 

BUT..

Child support often does NOT cover the things you are talking about.. medical.. extra curricular sports.. and other sundry items.

Child Support generally is intended to cover the basic needs of the child.. housing.. basic clothing.. food.. utilities.. transportation... it may not even cover child care.. depending upon how it is determined.

Now.. your situation is also potentially different because we don't know WHAT he is paying in CS (I mean..  you do.. but we don't).. and we don't know if it is appropriate or sufficient if it were to be guaged against your state's calculator taking into the fact that his EX appears to have the majority of the custody of both kids.

It is quite normal for a CO to dictate that each parent pay a percent of any out of pocket medical costs.. sports expenses.. and the split might not even be "even".. So.. because he just paid her money.. that money was for groceries.. electric bill.. towards vehicle costs.. and housing the two kids... when she asks for money for most of the other things.. that is theoretically normal.

What isn't normal (or shouldn't be).. is parents bankrupting themselves and spending every waking minute of their lives wrapped around their children's lives.  The sheer number of special (expensive) sports your "averagely talented" and "marginally motivated" SS is ridiculous.. especially when his academic progress seems lackluster.

The problem is that your DH can't stand up to his son.. or his EX to tell them that all these activites are throwing good money after bad.. that it's not good for the kid to be so over scheduled and that his grades need to come up.  But.. I think your husband LIKES the fact that his kid is in all these travel ball sports.. he may complain to you about the logistics.. but I think somehow.. some part of him is proud of his son for doing it all...

I don't think his EX is money grabbing for hte sake of money grabbing.. the activities they are in are expensive.. and medical is what it is.. but if the two parents cannot afford to support this level of participation.. someone needs to be the adult and put the brakes on it.

When I met DH, BM would just give him a handwritten list with an "amount" he owed her each month and he would pay it. There was never any proof of purchase or anything, just her word. I asked him why he was doing it and told him he should ask for receipts. She lost her mind then sent pictures of checks that had not been cashed and one was written out to the wrong name (easily verifiable), so it couldn't have been cashed. She then refused to pay for whatever DH signed the kids up for, saying they didn't have agreement, so DH said that was fine, he would also only pay for things he agreed to. She used sports to disrupt DH's scheduled time as well. And neither skid was super interested in anything. 

Then, because BM wanted to say she was paying for health insurance so she could get extra CS from DH, she had her lawyer add language to a revised agreement saying she would cover all the health costs. Then she tried to come back to DH to cover braces for second skid (first skid had braces that we paid for part of). DH pointed her back to the agreement. She replied, "you're just trying to ruin me!" even though it was her lawyer who added the language. Then second skid never got braces. 

Now, she's coming at DH for money for "college", even though she makes at least $400K a year (more than DH and I combined) and neither kid is really capable of going to college (or has any interest). It's February of senior year and neither one really knows what they plan to do next year. And we're not supposed to ask about school, because when we did, we were "just trying to make BM look bad!" or "just trying to make Skids feel bad!" according to BM.