The boyfriend with the twin sister was being affectionate *in public, in front of the family and his fiancée*, which doesn't give me the impression that he was trying to hide anything.

And the bit about the "Santa" thing being a family tradition of many years also makes it seem more on the up-and-up.

It's not *impossible* that there is more going on behind the scenes, but I find it unlikely that they'd be so comfortable being demonstrative, if they were trying to conceal a massive secret.

I mean -- I'm not on "cuddles" terms with any member of my family (my daughter and I are very close, but we don't snuggle much now that she's an adult -- we hug and hand-squeeze and such), but my family-of-origin was also VERY standoffish and cold about physical affection.

So, it would feel a little weird to me to see a partner cuddling a parent or sibling . . . but I wouldn't mentally jump to incest, I'd just find it a bit unusual in comparison to my own upbringing. That doesn't make it wrong!