It bugs me when SD9 hangs on my SO! Check out the blog called "It's me again and I have taken a stand". If you go to "blogs" and scroll down you should see it, it's new. She has a few posts about her SD11 doing this.

Not ok though!! He needs to set boundaries.

Ugh. I feel for you, elcamino67. It’s such bizarre and inappropriate behavior. What is up with these preteen/teen daughters and what appears to be an Oedipus Complex? 

there has been times we have been at the mall and they were holding hands and he would hold my hand at the same time and people would look at us like he had 2 wives or something.

I hope you quickly and instinctively let his hand go in these situations, because nope, no, nah. 

He’s gaslighting you by telling you that you are jealous.

Don't confront with anger or even reason.  Just make fun of them and ridicule them - especially publicly and on social media.

For God's sake do not let others think you are okay with this sh*t.  It will make you look like a "prevert" too.

No wonder he doesnt cuddle you apart from when he wants sex, he gets it all from his daughter.  

I agree with others, this is not normalor healthy, it is dysfunctional. I think you will have a big fight trying to change this and you are unlikely to win. He always defends them as you say, he must be afraid of saying no to them. 

Its hard to suggest anything but i think maybe you should speak to a family counsellor or some sort of relational expert who might be able to suggest a way for you to tackle this with him. 

They walk around holding hands with their fingers interlocked?! I cannot even imagine...*shok*

SD who was at the time 11 would act so needy and wants to sit on her father's lap. I think thats too old to be sitting on a man's lap. She wants all the attention and will swear to the gods she doesnt but I see otherwise. This one time she sat on his lap. legs apart with his leg in between and she would wriggle and move around and lay back on him. And in my head Im thinking this is effing weird. Becasue anyone who as ever sat on a bench or a narrow whatever legs apart knows usually your private part is touching whatever you're sitting on. I was younger then and didnt speak up. SD is 15 now and she has somehow convinced her father to pay her cell phone bill every month even if he is struggling to pay other things. Texting little stupid hearts. I dont think Im overreacting. I honestly think something isnt right. So she is visiting now and for some odd reason her brother who is an effing adult +18 thought it was okay for him and his 15 y/o sister to sleep on a darn sofa together for 5 days straight. Even though he has a bed. He would always make a point to sit next to her. Its creepy. I dont think I will ever understand that type of sibling bond. But the father never said anything. So instead of me saying something, I told him to tell his son that was inappropriate. Now, back to when SD was 11. I remember her and her brother(different brother who at the time was maybe 15) were awake, with covers over them but not covering their entire body. He had boxers, she had only underwear(again she was 11) It fricking 2pm and theyre still in the bed. He had actually gotten into the bed with her and they were just talking. I told them to get up and get dressed. I had mentioned it to their father. But, honestly I dont think he would have mentioned anything about the weird behavior.  Currently, she is 15 and wear the shortest shorts and crop tops. Pajama short are what we would call b00ty shorts. I'm not sure if I was to actually say that this but I dont know anymore. It all seems too weird . They will just think im jealous and probably because I dont want the SK in my house anyway(mainly because SD and the other daughter are disrespectful. Please respond and tell me if you think the entire family is weird. I think I should walk away but its my house and my husband refuses to leave

Remind her she's the child. Tell her to stop acting like she's her dad's date, its embarrassing. Remind your DH that you are his wife and she is his child. Until he can understand the difference he can sleep on the couch. Yes to posting this behavior on social media, let him see what it looks like to others. Take back your place

I m married to DH with two kids... SD 15 yrs old and SS 8 yrs old ...i can totally relate to you...my SD is like my DH mini wife...she sits on his lap... hold hands in public and my DH even buys underwear for my SD...it is very strange to me because my father was never like that..my DH cannot hear a single word against my SD...my SD acts like an angel infront of her DADDY!! but in reality she is demon!!! I really feel for all the Step mothers out there ....Good luck all!

My situation is similar except that we are not married but living together. SD 17 lives with BM, and it's a similar shit show, you can read my blog under Greatlove. 
I confronted him about it when we discussed going to Berlin for 3 days with my 2 badass daughter (19 and 25) who visit us from the US. I have a tendency to blow up which is counterproductive. So first, I wrote down what I was going to say, because I talk myself into a rage and veer from the topic, which was your daughter can't come with us to Berlin unless she brings a friend because I'm not dealing with the shit show. Then i memorized it. 

When he came home from work I told him I needed to discuss something and needed his full attention. He said let's lay on the bed and talk. I held his hand and started. Holding his hand kept me grounded in that I love him and that in all other aspects he's a great guy. I said my piece, stating SD can't come etc, and then asked "can you agree to that?" And he said yes. I was prepared for him to say that she will come no matter what, and I was prepared to say that he was then uninvited to findige me and my girls.

What may be helpful is that you focus on one specific incident to address, so it has to be one at a time. These kinds of dads established a sick pattern with their daughters long before we got there that takes time to undo. Mine was not aware how fucked up the shit show is.

Asking "can you agree to that?" forces him to decide, and gives you a clear answer right then. Depending on what it is you can decide for you what you want to put up with and for how long. 
 

I wish you all the best and hope you keep us updated.