Is it a bad idea to date a senior boy in high school when you are a sophomore?

I don't think that's bad.

There's nothing wrong with dating someone older then you. It's not like it's illeagle.

Answer

No, just go slow. Alot of times when seniors are getting ready to graduate, go on to college, they begin a new phase in their lives and the past is the past. Talk with the guy and see what his intentions are and keep your eyes and ears open. Dont rush into sexual contact either because it too can wait.