Another post on here made me think of something that my SO recently told me:
My SO has 2 daughters, almost 12 & 13 ... the 13 year old is maturing much much faster than the 12 year old. The 13 year old just told Gma the other day that her dad doesn't hug her or kiss on her like he used to but he does all the time with the 12 year old. When he told me about this, I asked him if he notices that and why he's like that. He bluntly said, "Because I don't want to feel her boobies when I hug on her. The other one is still like a little kid and not a pre-teen. She's not maturing the same so it's easier to hug on her and tickle her like I always have. I just can't do that with the 13 year old. I am uncomfortable. I feel bad saying that because she's my daughter, but I am." I told him maybe he needs to back off more with the younger one so the older one doesn't feel so "left out" and "awkward" about it or like it's coming across he loves her less .... thoughts?