Once a cheater always a cheater? I need help =(

I have a boyfriend of 7 months.
last year , he cheated on his ex girlfriend at a party,
he never wants to talk about what he did but I do that I was more than just making out.
Im only 16 but I have a real issue with trust, and im always thinking about how he cheated before , and im a strong beleiver of "once a cheater always a cheater". I really want to trust him but I just can accept the fact that was in the past. im just scared he'll do it with me. any advice?

well the onlii thing I can say is just go wit what your hearts says and try to beleive that he ant cheatin cause I belive in that sayin to but sum people change

I understand where you're coming from....but unless there are signs of him doing things that would because you think he is.....you really shouldn't worry. Some people who cheat will always cheat...but again, there are those who have grown up and realize they made a stupid mistake... Try to trust....without it there is not real love.

You should never start a relationship with one or both parties cheating on someone else becos the relationship is doomed from day one becos of the trust and always wondering. If you cannot trust him you should leave him becos you'll never truley be happy.