Anyone had a bad experience as a teen hooking up with an older person?

Sure. It’s all fun and games, until it all goes downhill, and that’s not an “if”.... that’s a definite “when”. You’ll have regrets galore. God is against it. It is one of His commandments. It is violating what is supposed to be the sacred sharing of spirits and body in holy matrimony. Whoever you sleep with, you become one with in spirit and body. God takes that seriously. Fornication is a sin. That’s not the way God set things up, and He sets the standard for morality...not us.