1 Work in Avengers Big Bang
"Okay. So. Kids. It can't be too hard, right? People dumber than us raise kids all the time. Not much to them. Just feed them, water them, distract them with shiny things and make sure they aren't unsupervised for too long. Speaking of which, how long has tiny-spawn been alone in your kitchen?"
Steve and Tony (and The Avengers!) from the movie!cast + child!Peter Parker with a very AU backstory involving genetic experimentation aboard an abandoned space station (but that doesn't--strangely enough--feature all that heavily).