Q I’m 28 and my girlfriend of the past eight years is 30 years older than me. I love her dearly but I want to have children and this is obviously not possible with her. We have great sex and she has taught me so much, but I don’t want to be her carer as she gets older and the life that I envisaged for myself includes children. Should I end the relationship or stay with the woman I love?

A When a woman of 50 chooses to form a relationship with a boy who is just out of his teens she does so knowing that his level of maturity is not going to be the same as hers. She also knows that shared interests and great sexual chemistry are often not enough to sustain a regular relationship, let alone one with a 30-year age gap.

Older women tend to be realistic about the level of commitment they can expect from a younger man. When you and your partner first met I doubt that she would have put money on you sticking around for eight weeks, never mind eight years. In fact I suspect that she treated it as casual for a very long time, but the great irony is that in removing the pressure to commit, an older woman often increases the level of attraction because the male feels that the relationship is not complicated by hidden agendas.

Relationships between older women and younger men are mutually beneficial. For an older woman, a younger lover is often more open-minded, curious, energetic and challenging than her previous partners. For a young man, an older woman is usually more confident, stable and experienced than younger, more age-appropriate girlfriends. The downside is that, in the long term, differing needs and wants can create conflict.

An older woman needs her beauty sleep. A younger man wants to go clubbing until the early hours. She wants to spend six months in Spain. He needs to stay in the UK and work on his career. She may be finished with bringing up children. He wants the option. You’re probably not even ready to have children yet — most men in their twenties are more concerned with preventing than having babies — but the age gap between you and your partner has forced you to consider what kind of future you envisage for yourself well in advance of it actually happening.

It’s a tough call — and there are lots of pluses to remaining childless — but if you are truly intent on having your own biological children with a fertile partner then you do need to end this relationship.

You are right in thinking that the longer you leave it to address the issue the harder it will be for your partner. The success of your relationship has already exceeded everyone’s expectations and the danger is that your partner may now have lost sight of any objectivity she once had about its long-term feasibility. There is no doubt that a break-up will be very hard for her. The prospect of turning 60 as a single woman holds very little appeal for someone who has grown accustomed to a constant companion, but if you are truthful, kind and allow her to maintain her dignity the end of your sexual relationship does not have to be the end of your friendship.

Certainly, negotiating your exit from this relationship on the basis that you want to have children at some point in the future will be much less hurtful for her than the alternative: sticking around until you find someone half her age and then leaving. If you do decide to split, keep quiet about the fact that you are worried about becoming her carer, though. It does not reflect well on you and it is disrespectful to her. You have a fantastic sex life with her and she is obviously in good shape, so don’t undermine that confidence. Women tend to live longer, healthier lives than men anyway, and you should also realise that there is absolutely no guarantee that accident, illness or even childbirth won’t leave you caring for a much younger partner. Or vice versa.

Remember, with love comes responsibility. And with maturity comes compassion. At any age.

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