I kissed someone else and am not going to tell the guy I am dating.
Why wouldn't you tell your partner you kissed someone else?
I am upset, embarrassed, and just want to forget it ever happened.
It is not healthy for a relationship to keep a secret like this. You are better off telling your partner about what happened before the stress eats away at you.
Ah, the guy won't be upset with me and I don't want to dissapoint him
But don't you think he deserves to know the truth? It's better to tell him now and not just let him find out in the future.