<human>: Ive been with m girl for 10 months now. Last night i had a coworker over after a pizza night and we started kissing deeply. Thats all that happened though

I know what I did was wrong, and frankly there isn't a specific reason that I cheated. I just messed up. 

I feel pretty awful, and I know for sure my girl would be absolutely devastated if I told her. The thing is, she's leaving to the air force next year. Should I tell her and put her through a that pain even though we won't be together for much longer?

I know for a fact that I'm never going to cheat on her again. I believe I've learned my lesson and quite frankly, I realized after what I did that no one else can compare to her. 

But is it really worth telling her and breaking her heart? Or do I just try to give her the best I can offer while I still have time with her?

Condense the text into a few key points
<bot>: Girlfriend and i have 1 year left together. Do I tell girlfriend I cheated and break her heart, or give her best I can for our last year.