This is such a sensitive issue because there are four major relationships that could be affected — your relationship with your fiancé, his relationship with his friend, your relationship with your best friend, and her relationship with her husband. If you say something, you risk damaging or possibly even ending any of those relationships. You risk not being believed. You risk a potential “he said/ she said” scenario where your friend’s husband calls you a liar and produces his own story of the events, either saying you’re making up the entire thing or that you were the one who came on to him.
If you don’t say something, you risk sending the message to your friend’s husband that you’re OK with his behavior — especially since you didn’t stop it immediately when it was happening. You risk letting him behave this way to you again — or even “holding out hope for a foursome.” You also risk feeling guilty if your friend’s marriage suffers, knowing that you had insight into her husband’s behavior that you never shared with her.
You really have to weigh the possibilities and decide which scenario presents the lesser risk. If it were I, I would probably opt for silence, and then never, ever get drunk around that particular person again. I would also cut back on double dates and make excuses for hanging out together as a foursome (oy). With the holidays coming up, that might be easier to do — you have the excuse of being busy with family, going to work parties, maybe traveling, and, of course, you’re busy planning your wedding.
What I would NOT do is only tell your fiancé and not tell your friend. If you decide to say something, you have to say something to both of them. Your fiancé is going to hear that his friend rubbed his erection on you (oy, again) and he’s going to go after the guy. You think that’s not going to get back to your friend? Maybe it won’t. But there’s a good chance it will. There’s a good chance that her husband will either confess OR tell her (and your fiancé) that you lied. Either way, if your reason for not telling your best friend is because you don’t want to put a strain on her marriage, then you shouldn’t tell anyone.
One final option is to say something to the guy who came on to you. I would do this in person or over the phone — not in a text or email that could potentially be found by the wrong person. I’d say something like this: “We had a lot to drink the other night and some inappropriate things were said between us. I love my fiancé and I love your wife and I would never want to say or do anything to jeopardize those relationships, so I suggest we move on and never, ever let a conversation like that happen between us again.”
And then move on and never, ever let a conversation like that happen again.
If you have a relationship/dating question I can help answer, you can send me your letters at firstname.lastname@example.org.