Is it common and WHY?

I’m guessing it might be normal that a man would feel awkward or weird and thus hesitant to interact with their baby while it’s still in the womb, right? I ask my fiancé to rub my belly and he hesitantly does it, but not on his own accord. Something seems wrong and I don’t know what it is or if I’m just overthinking. It hurts my feelings and makes me think he’s not fully up for helping raise the child. Can someone please give examples or experiences of this?