Trust

Ok so if the one person you love goes behind your back and does something wrong how do you trust them again

Nope - once someone betrays my trust once I never trust them again. That's just me though, what you do is completely your choice.

Well unless you feel you can never trust him/her again. Then I guess that trust will come back slowly overtime as look as the person doesn't do anything hurtfull again.

I would trust them again, it doesn't even matter what the person did (in my opponion) every one deserve second chances... you learn from your mistakes, and you become a stronger person cause of it, this COULD even be a chance for you to become closer

Im a senior now but when I was in middle school my best friend broke my trust and in the back of my mind thats still there. Even though I trust her with a lot I still have trouble fully trusting her. It just takes time though. There is a chance you may never be able to fully trust them again but if you really want to start out with something small and build up.