Why does my 15 year old daughter think it's ok to like/date a 22 year old guy?

I was the same way in high school. My parents obviously didn't understand me, of course I was mature enough, etc., etc. If you want to actually talk to her about it, you can stress the facts that 1) a sexual relationship between the two would be illegal in most states and 2) they are at very different stages of life. Honestly, she'll probably figure out on her own that such a relationship would be inappropriate. But even if she doesn't, you her mom and are still allowed to ground her or punish her for seeing him. Sometimes we need that kind of tough love--I definitely did.

Maybe you should inform her of the fact that its considered statutory rape and that he can go to jail for it. Also maybe it would be a good idea to have her talk to teen moms, ones who got pregnant and ended up being left.

Maybe you should be a parent and discipline her... Report the guy, he's a pedophile and you know it. Stop encouraging it, step in.

Maybe she thinks he will be or is more sensible/mature than guys around her age. Teens males around her age will be loaded with testosterone and you know what that means.