She doesn’t know I’ve had sex with our mutual friend

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Dear Meredith,

I'm in a relationship with a wonderful woman I met through our mutual friend. The more serious we get, though, the more concerned I get about a certain issue. I feel like there are things in my sexual past that would make her really upset. After my divorce, I had sex with the woman who introduced us to each other. This happened about a half a year before my girlfriend and I met. I'm pretty sure she doesn't know this and it terrifies me. I really don't want to know anything about my girlfriend's sexual past and I don't care about her knowing about mine either.

I'm afraid that someday, she's just going to flat out ask me if I've had sex with our mutual friend and it's going to look terrible that I'll have to admit I have. Then it would look even more awful that I never volunteered the information. I really wished I never slept with her. It sucks. There's also the chance that if I did tell her, she'd be upset that I told her something she really didn't want to know. It's like being best friends with a security officer that guards the bank I robbed once. I truly don't know how to handle this situation, but it's starting to seriously weigh on my conscience.

– Concerned

"It's like being best friends with a security officer that guards the bank I robbed once."

Wait, what? No it's not.

Based on what you told us in your letter, you had a consensual sexual experience with a friend (right?) but decided it wouldn't/shouldn't lead to more. That intimacy is part of your history with that friend, but it has nothing to do with how you feel about each other in the present.

I'm not even going to give you another metaphor to work with. Nothing involving banks. Let's not over complicate it.

My question for you is why this is weighing so heavily on your conscience. Is it because you still have feelings for this mutual friend? (I don't get the sense you do.) Or are you someone who believes that any unshared detail about your past counts as a lie of omission? I guess I believe that people are entitled to their own secrets and histories. Your girlfriend doesn't have to know everything, and you're right, she may not want to.

I guess my thought is that if you do tell her – and it sounds like you want to – give it the weight it deserves. It doesn't have to be an "I have something terrible to tell you!" disclosure. It can be an honest, "I've always wondered whether you knew that right after my divorce, when I didn't quite know what I wanted, [mutual friend] and I had a night. Clearly, it led to more friendship. Not very interesting, but I never wanted you to be blindsided by that piece of our history."

But please, no matter what, think about why you're so stressed about this. Does this "wonderful" woman seem like someone who'd get angry? Leave you? Or are you just so happy about this relationship that you're trying to troubleshoot before anything bad happens?

Consider why you think she'd be so upset about your past. You might want to spend some time unpacking that yourself.

– Meredith

Readers? Should the LW disclose? Would you want to know? What does this say about ... anything? Better metaphor?