My girlfriend of five months is into the fetish scene, has other partners and considers herself polysexual. Originally, I thought that this would be OK, but now I've fallen for her hard. She has moved in with me but has other lovers that she talks to and texts all the time and I can't help but get jealous. She says she wouldn't mind if I played around with other women, as long as she remains my number one – but I don't want to. It tears my heart out to think of her with another man. How do I quell these jealous feelings?

Jealousy is a normal emotion that serves an important social purpose. Some people find ways to reframe it, but achieving emotional control in your situation is unlikely without a huge amount of work.

You are both torturing yourselves with what may be an impossible situation. The relationship you're attempting is one that requires extremely careful negotiation, enormous vigilance, and constant re-evaluation, plus an emotional and sexual sophistication that few people achieve. Even within the framework of an open relationship, limits and boundaries must be set.

You must both lower your expectations immediately, soberly recognise the difficulties inherent in achieving a relatively painless, consensual open relationship, and get back to basics: expressing feelings as they arise, listening to each other, and respecting each of your emotional challenges.

• Pamela Stephenson Connolly is a psychotherapist who specialises in treating sexual disorders.

• If you would like advice from Pamela Stephenson Connolly on sexual matters, send us a brief description of your concerns to private.lives@theguardian.com (please don't send attachments).