No doubt Stark's been around the block. Say one of the women he has had "relations with", comes forward and says that her kid is Tony's and he needs to pay up or do something about it.
Now here's the kicker. The mom's only money hungry and is pretty much a jerk towards her baby's daddy. The kid's grown up (say 16-19) and he's really smart. In fact, he's got the potential to be just as smart as Tony. But he's a cokehead. He's very neutral in terms of personality. He's not a hero, but he's not a villain either. He's just a really smart dude who happens to be a cokehead and his mom's a greedy (insert generic insult).
How does Tony deal with this situation?