DEAR ABBY: I am a 17-year-old senior and have been dating the same boy for two years. A month ago, he told me he wanted to break up “because he needed some time to figure out what he wanted.” I was devastated but agreed. Two weeks later, he told me he was sorry and he loves me. We are back together now, but the weekend after our breakup, I went to visit a college girlfriend. We went to a party and I ended up having sex with a boy I didn’t even know. I feel guilty and unworthy. What should ...