We have a male friend in his 30s, our friend group is a mixture of people from their early 20s to early 40s, very large, some with kids some without.
I can't tell whether it's just him being a total narcissist or something deeper.
He is obsessed with spending time with friend's kids and getting them to like him. He's not got kids of his own, hasn't tried, has a partner who doesn't want them yet.
He is just constantly making jokes around them and is very gleeful around making sexual comments (not child related) in front of the children, he loves being Uncle _, shows the most attention to one particular child and wants this child to think he's amazing, etc.
I'm probably just looking too deep into this, but it does seem strange that he's so desperate for this child, someone else's child, to absolutely love him. The child isn't massively receptive. I feel like even though he's probably a good guy, when she grows up she'll probably think he's a bit strange too.
Even women aren't this desperate for other people's children (with no blood relationship) to love them, and we're supposed to love kids.