DEAR DEIDRE   My girlfriend and her pal are pestering me for second threesome but I’m not keen

DEAR DEIDRE: I HAD a threesome with my girlfriend and her best friend. It was amazing and they’re talking about doing it again but I don’t think it’s a good idea.

I was at my girlfriend’s house one Saturday night when her mate texted to ask if she could come round. I said that was OK by me. I’m 21 and they’re both 20. If anything, this friend is better looking than my girlfriend but she has a bit of a reputation for sleeping around.

My girlfriend’s parents had gone out for the evening to a ­silver-wedding party so we were on our own. I drank beer, the girls had some prosecco, we watched a film on Netflix and cooked a pizza. We were really enjoying ourselves and having lots of laughs and jokes.

My girlfriend’s friend then started teasing me and asking me personal questions — like how many girls I’d been with and if I’d had a threesome.

When I said no, she suggested we have one there and then. My girlfriend wasn’t shocked, as I would have expected. In fact, she seemed up for it.

We all started kissing and touching one another. Soon we were stripping off and having sex there in the lounge.

It was amazing. They were all over me. Afterwards we all said we didn’t regret what we’d done and it was great fun. Her mate and I went home before my girlfriend’s parents got back.

The next day I saw my girlfriend and she talked about nothing else. After that, she and her friend kept messaging me going on about it.

She keeps bringing it up as something to look forward to now that she’s at home with her parents and I’m stuck at home with mine. But I don’t want to, now I’ve thought about it.

Suppose something went wrong with the condom and one of them got pregnant? I talked to my girlfriend but I can tell she thinks I’m weird and a wuss.

How can I get through to her that this was a one-off and I’m not up for it again — without her thinking I’m boring?

DEIDRE SAYS: Sometimes we have to stand up for what we believe is right and our best course of action without worrying about what other people think.

You have good reasons to have decided against more threesomes. There is the risk of pregnancy, spreading sexual infection, plus the emotional fallout. My e-leaflet Thinking Of A Threesome explains.

You sound like you feel a bit used and must wonder if your girlfriend really cares for you deeply or if you are just a step on her sexual journey.

So tell her straight you are not up for another threesome, spell out your reasons and be firm. My guess is she will respect you for it.

If she sneers, you know she was never the girl for you long-term.