I love letters like this one, because I get to embrace my inner Dan Savage for a few moments. A reader writes in with an interesting dilemma. He says, “Recently my girlfriend and I began hanging out with a local coven. She is spending a lot of time (without me) in the presence of one of the group’s other male participants. She has said that she’s very attracted to him, and even hinted that she wouldn’t mind sleeping with him. I objected to this because honestly, I’d like our relationship to remain monogamous, but she seems to think that since “all acts of love and pleasure are my rituals,” that…