Originally Posted by
Tiamatty
The Bastard Son Of Tony Stark, maybe. I have two different ideas for it.
First version: Back in Tony's playboy days, before he became Iron Man, he had a fling with an aspiring starlet. Maybe a Nicole Ritchie-type, a girl born into money who never needed to work, and wanted to be famous, and was briefly famous, but who quickly disappeared into irrelevance. A woman like that. So Tony slept with her, and knocked her up, but never knew about it. She had a kid who had some success as a child star, but, once again, became irrelevant when he hit his teens. Now, the kid, at 18, has learned that Tony Stark is his father, and decides to try to use Tony's money to become famous again. The kid would be a smug little prick who parties too much, and Tony would hate him and want to throw him off the top of Avengers Tower, but feels some sense of responsibility, so would try to help him.
Second version: During a mission in some random location - Nebraska, or New Zealand, or Nigeria, or even somewhere that doesn't start with an 'N', but which is way outside Tony's usual stomping grounds - Tony met some female hero. They worked together, and Tony slept with her, and then he went back to New York. The woman had a kid, and did her best as a single parent. But now the child is developing powers, and the woman isn't sure how to deal with that, so she calls Tony for help.
In both versions of the story, everyone's reaction to learning about the situation is, "Wait, you have a kid? Actually, never mind, I'm more surprised you don't have more kids running around out there."