sd12 almost 13 had a terrible problem of this when I first came into the picture. But I think that my reactions and comments have helped a lot.

She still hangs on him from time to time but now he tells her to stop. There is a time and a place for rough housing play. But it's not something that needs to happen all the time or every single day.
And there is never a good time for a 15 year old to be hanging on a man regardless of if they are related or not.
I see so many kids that don't see to respect anyone else's space.
I have a friend that her daughter did this continually, hung on every single guy around... she ended up preggo at 17 and doesn't even know who the daddy is, plus she just goes from man to man.

It was the writing on the wall but her mom didn't want to see it.

yes it is creepy SD13 will hang all over SO sit in his lap when they watch TV it creeps me out, he told her she was too old for that and she has stopped. But when we go out in public she holds his hand and at restaurants has to sit and inch away from him. He stops that too and she pouts. Oh well she needs to get over it }:)

Just Tired, you must be ME in another body. I just spoke about this in my blog a few days ago about our family vacation.
Here is an excerpt.

SD11 was all over my DH. If she saw him near me, she'd come and interject. We were a large group. During dinner, kids ate at one table adults at the other. She'd continuously come over to our table to rub her fathers face and head. After I had had enough I started mimicking SD by dramatically rubbing my face and saying maybe a genie will jump out and grant me a wish! SS19 leaned over to DH and stated that I was jealous. Hmmm, no says the voice in my head, I think you're little sister is acting fucking creepy, but whatever.

Also, this past weekend, she did the following:
We were at a BBQ, she sat next DH, lay her head on his lap. Held hands with him. Stroked his leg.
While he was laying down on the couch watching tv, she laid her entire body on top of him so she could tell him that she wanted ice cream. It is gross, disgusting and VERY VERY creepy.

I keep having visions of the movie ORPHAN.