Born and raised mormon. Masturbation and porn are evil. You are not allowed to go past kissing until marriage. They make it very clear but can turn a blind eye to making out/dry humping. If you engage in oral sex or touch body parts that "aren't worn by a swimsuit" you have to confess to your bishop (church leader) and he puts you on some kind of "spiritual probation" (for me it was 3 months) where you can't take the sacrament (church ritual) and you have to repent of your sins by reading church rhetoric, praying for forgiveness, etc.

You cannot marry in a mormon temple if you have premarital sex. You can't go on a mission, and if you're going to a mormon school, you will get kicked out. Getting married in a temple and going on a mission are two mormon "rites of passage" that should be completed. Mormon girls want to marry return missionaries. They want temple marriages to "righteous priesthood holders." The kicker is the stipulation that one can be with their family and loved ones in heaven but only if they get married in a mormon temple. If you don't get married in a temple you will not see your family after death.

Mormons place premarital sex as the "third worst sin to murder and denying the holy ghost" and requires a yearlong bout of abstinence and the above repentance process as listed above in order to get married or be a worthy mormon. Since your boyfriend is a senior in high school, he isn't endowed, so he won't get disfellowshipped/excommunicated.

I just want you to be aware that these are ideologies that are instilled in us from a very early age and are very hard to shake off. The first time I was fingered I was 19 and I cried from guilt and shame. The first time I had sex was when I was 20 and I was shocked about how much of a big deal it wasn't. They make "worldly sex" such a huge deal all the time. It's not.

Based from what I read he's analyzing what happened. Talk about it. He's 18 and at a crossroads. 18 is mission or move out and start over age. If you both are thinking long term, he would have to not be mormon. Don't take it as him being "better than you or that you're corrupting him." Dating an atheist was a catalyst to my falling out, which was ultimately my choice. Do not, please, convert to be with him if he goes the mission route.

If you're talking short term, indicate that you had/have no idea how intense mormon ideology is concerning physical intimacy and go from there.