Dear Annie: I’m in my early 20s and have been dating “Aidan” for a year. He attends college two hours away. He doesn’t socialize much and stresses a lot about his grades. His only real friend is “Cara,” a girl we went to high school with. Cara lives in a house with several other girls. The first time I met her roommate “Lisa,” I felt uncomfortable. I’m not the jealous type, but something about her bothered me. Still, I continued to be nice to her and supportive of Aidan’s friendships. A few days ago, Aidan came clean and told me that he had drunkenly made out with Lisa. He said he was stressed over school and went to see Cara, but only Lisa was home. He got drunk, and they got overly friendly. He said he felt terrible and was tormented for a week before he told me. He promised it would never happen again.