The dilemma I have started a physical relationship with a woman I met playing netball a few years ago. I was attracted to her immediately, but she was aloof, though eventually we became friends. At a few socials she tried to kiss me, but I politely refused knowing she was married.

Then we started working in the same company and one evening, drunker than usual, I made a move and we’ve progressed from there. It feels really good when I’m with her, we’re into the same things and I enjoy her company.

We know we should end it and talk about it almost every time we meet up. It just seems to be getting harder each time. She doesn’t want to go ‘cold turkey’ and wants to stay friends. I’m not sure it’s possible and would prefer to stop at once. But am I going to have to get a new job and stop playing the sport I love to square this wrong and deal with the karmic issues?

Mariella replies I certainly wouldn’t be so extreme. You’re not describing undying devotion here, but a pleasant and pleasure-filled friendship with frills that has suited you both. In normal circumstances I’d advise against having an affair, but you’re already immersed in one and it’s worked reasonably well until now – aside from the guilt.

If you didn’t enter the relationship with dreams of a happily ever after there’s no need for this closing chapter to be cause for conflict. Elevated emoting would be incongruous if the circumstances are as you describe. There are three possible futures for this romance: she returns to her husband (not so romantic for you); she leaves her family (painful and disruptive for many); or you sacrifice your sexual adventuring for more honest partnerships on both sides.

You are women, not volatile teenagers, so you should be able to behave like grown-ups when you end the sexual side of things

As you describe it you’ve fallen together through mutual attraction. Your girlfriend is the one who’s going to be missing out if her attraction to women is more than unique to you. In the best possible sense she’s got good reason to string you along for the foreseeable future. You, on the other hand, are leading a clandestine life when you could be embarking on a union that might have a future.

If you’re discussing separation every time you meet then it’s definitely time to part. It is possible you may be downplaying your emotional investment to protect yourself against disappointment. A wise thing to do when there’s such an imbalance between partners’ emotional availability. But there’s no point in writing to me without giving me full disclosure. It’s tricky to answer your dilemma while I have this niggling feeling that you haven’t been entirely honest with me. If it’s simply a case of wrapping up a relationship that has run its course and doesn’t have a likely future, then no dramatic action is required.

As always there’s another version of the story that would complicate the break-up – that is if either of you nurses ambitions for a more permanent relationship. When you are having an affair it’s natural to try and deflate expectations and downplay the depth of your feelings. It would be an act of masochism to immerse yourself in a full-blown love affair when the likelihood of it leading to anything but eventual heartbreak is slim to zero. It would also be entirely human! I’m wondering if what you’re really asking is how hard the heartbreak will be to bear of having your lover in close proximity when you are no longer entangled?

Well, you are adult women, not emotionally volatile teenagers, and you should be able to behave like grown-ups if you make the rational decision to end the sexual side of things. Of course there will be difficult moments in the aftermath, but with no blame or shame what’s to stop you reverting to your past friendship? In maturity best friends are often those who we’ve known intimately. We hold few secrets from ex lovers and in many cases they are the people we can be wholly ourselves with. Any good and sustainable union requires equality and yours is no different.

This woman is living a lie. She’s deceiving her husband, who I presume believes her to be his committed partner, and she’s expecting you to be her accomplice. It’s an unfair role to have thrust on you and an uncomfortable position to be in. You shouldn’t have to feel ashamed of your affair. Now is the moment to graciously abandon what’s not yours and find a better focus for your affections. With grace, dignity and maturity there’s no reason for this relationship to end in acrimony.

Celebrate the intimate times you’ve shared, restrain yourselves from having any more of them and focus any excess energy into netball and your job. It won’t be long before some other fabulous femme catches your eye – and I’d recommend holding out for one who isn’t involved in a timeshare.

If you have a dilemma, send a brief email to mariella.frostrup@observer.co.uk. Follow her on Twitter @mariellaf1