‘I’ve been sleeping with my girlfriend’s sister. I need help. What do I do?’

Ask Roe: ‘My girlfriend is a frontline worker, so her sister and I were together alone a lot’

This letter is from "Dear Roe, dear Trish, dear John: Your thorniest sex, relationship and parenting problems", a selection of readers' questions about pandemic-related difficulties. You can read the full article here

Dear Roe

My girlfriend and I are in our 30s and are living together. Her younger sister moved in with us at the end of last year. She was meant to stay for only a couple of months, but coronavirus has forced her to stay longer; she’s unemployed. I was delighted at first. I now had two beautiful women living with me.

But my girlfriend is a frontline worker, so over the past few months her sister and I have spent a lot of time together, alone. One night after dinner (and a bit of wine) she confessed she’s fancied me since she was 15. Long story short, we’ve been having sex for the past few months while my girlfriend is at work. Sometimes I’ll have sex with the sister at night, then have sex with my girlfriend when she gets home in the morning.

I'm absolutely torn with what to do. I know this can't continue, but I love both of these women now. Whatever happens, I'd hate to tear their family apart. (It's just the two of them and their mother.) To make matters worse, I think my girlfriend is getting suspicious. I need help. What do I do?


I’ll be honest, I was not expecting to get so many Covid-era letters from people sleeping with their partner’s relatives or relative’s partners. My immediate assumption is that this letter can’t possibly be real, but seeing as it’s merely the most extreme version of several letters I’ve received on the same theme, let’s roll with it and address everyone using Covid as an excuse for their disintegrating decency.

Cheating is never an accident, never suddenly happens out of the blue. It’s a series of decisions, a series of crossed boundaries. And your truly unforgivable betrayal of your girlfriend began the second her sister came into your house and you decided to think you were delighted to have two beautiful women living with you.

You decided to look at your girlfriend’s sister as a sexual object. You decided to revel in the idea of having two women living with you. You decided to indulge the initial flirting, because you value your ego and your fantasy of having two women wanting you more than you value anything else. Even the way this letter is written is a brag, because part of you loves the fact that you’re sleeping with two sisters.

You don't love anyone here apart from yourself. You and the sister have already decided you care more about your own desires than your girlfriend and this family; your fears now are just about getting caught. Break it off with the sister and tell her she has to leave your house. Tell your girlfriend what has been going on. When she kicks you out, don't dare feel sorry for yourself. You chose this. Choose to be better.

Roe McDermott is a writer and Fulbright scholar with an MA in sexuality studies from San Francisco State University. She is researching a PhD in gendered and sexual citizenship at the Open University and Oxford

If you have a problem or query you would like her to answer, you can submit it anonymously at