I know they exist - just about - because I've found the very odd pair on ebay. Basically, what I'm looking for is pairs of pull-on leggings with feet, exactly like the bottom half of a babygro. I think they're called leggings. I need some because we've got a lot of 'vests' (another confusing term, but I mean those legless, poppered, short-sleeved babygros) and granny-made cardis, and I wanted something to cover his bottom half without having to faff about, putting his socks back on every few minutes. No, he's not here yet (33 weeks) and yes, I am a Noob mum!
Actually, is there any reason on earth why a boy baby can't wear tights? (apart from that they look like murder to get on.) Aside from the fact that my m-i-l would probably disown me for cross-dressing her grandson...