I'm a bi woman in my mid-20s in a great monogamish relationship with my straight boyfriend. We occasionally invite other women into our sex life, which is really enjoyable for both of us. He isn't threatened by other women, only by other men, which isn't an issue since I'm not interested in any other men. So on the occasions when we find a lady we're both into who's also into us, anything goes, and it's awesome. We've hooked up with both friends and strangers, but always as a couple because it makes us both feel safe. That's all lovely. Enter the problem: I was visiting some friends of ours I used to live with before my boyfriend and I moved in together. After going out for drinks, we were playing an alcohol-fueled card game that turned into an alcohol-fueled strip card game. This is in my former home where I am very comfortable, feel safe, and was frequently in various states of undress while I was a housemate. One friend soon had her lovely breasts out, and she made a few comments that were direct and inviting and turned me on a little. I touched her boobs and sucked on her nipples, but that's as far as things went. Her boyfriend witnessed this but wasn't involved. It was a fun, playful moment, and soon after, I went to bed-alone. It wasn't anything my boyfriend would've objected to had he been there, but he wasn't there. Should I tell him about it, or is this a case where he has the right not to know? I'm not interested in pursuing anything further with this friend, and I'm not sure what talking about it would accomplish, other than being honest at the expense of my boyfriend's feelings, and probably making me feel bad for something that, although it seemed innocent and harmless in the moment, I shouldn't have done.