Get out of my head, you!

Had a horrible detail that now needs a story.

Real world, fantasy somehow, I'm not sure how yet. So far I only know the following totally random detail: there is a young man who fell head over heals in love with an older man, and it's wonderful, perfect, he's damn sexy, sure doesn't look/feel/act his age... and he has two kids, one of whom is actually older than Daddy's new playmate.

I know this detail because the playmate and the son want to have a very tense first meeting in a drabble I refuse to write on moral principles, such as not knowing what the hell is going on.

It's horrible. I think I like it. Now to discover whether or not the son wants to be the main character. I think Daddy and playmate may both be magically-oriented and son doesn't know about it... If only I could do plot.