<human>: Summarize the given text in a few sentences.

A couple of days ago was my girlfriend's birthday and she went to dinner with a friend, we'll call him derek, for a birthday dinner. She told me about it he day of, and I told her it sounds like a date, but I let her go because I trusted her. My girlfriend, we'll call her Amy, her parents are religious and will only let her go out with people inside their church. I'm not a part of their church so I couldn't take her out for her birhday. Before this there has been no.problems about infidelity so I completely trusted her. But she told me that after dinner, derek tried to kiss her and that she let him kiss her. But she pulled away after she let him. She told me all this, but I have been cheated on before and she knows that. She's telling me she's sorry and that she can barely look at me because she feels guilty, she won't even wear the necklace I gave her because of the guilt. I still love her, but I just don't know what to do. I'm so lost, never thought this would happen with her.
<bot>: Girlfriend kissed another guy, she told me about it, says she sorry and feels horrible about it, more lost than a blind man in the sahara dessert about what to do