>>23095829 (OP)
they've always seemed enthused in my experience, as though they like the attention, or bemused that you're curious
it's not a unique or special thing, but something fairly consistent
in exchange they're also curious: they sometimes like to do things like close your foreskin around their finger and finger you, or be picked up and carried around to see what the world looks like from a man's perspective, or stand behind you and hold your dick as you urinate—they have very coarse aim... but without a lifetime of practise, I guess that's to be expected