The dilemma After much heartache, sleepless nights and consideration I told my husband of two years, but partner for 15, that I was unhappy and thought we should separate. I am 37 and he is 49. On discussing our issues my husband said that if I left he would have no chance of children and I’d be robbing him of that as his chances of meeting anyone are very slim and mine are slightly better.

He has become a father figure to me. I feel I live in his house with his things and his rules. My husband is making me feel guilty for wanting to leave and leaving him childless and I do feel guilty, incredibly guilty and sad about that, and it is leading me to question whether I should leave. He says I am selfish. Am I?

Mariella replies Maybe, but that’s not important. Who isn’t selfish when it comes to making the choices that shape our lives? I’m afraid this all sounds like a case of too little too late. Which one of you is responsible for leaving your relationship untended for so long?

It’s a shame that having had so many years to make up your minds you went ahead and married only two years ago. Were any of these doubts on either of your minds then? Sometimes babies are made to patch up relationships; sometimes weddings.

It may be an error in your description of the situation, but your letter suggests that this recent discussion was the first of its kind. There are people who store up complaints and negative experiences, barely emitting a murmur, until one day they blow. You certainly appear to be one of them. If you wait until you simply can’t take any more, the choice to leave is pretty irrevocable. But sustainable relationships involve myriad minor re-adjustments on a continuous basis. You are “in development”, as they say in the movie business, for the duration of any partnership.

I can’t believe you’ve squandered 15 years treading water and am shocked at how little you value your lives

It’s a highly dysfunctional act to pronounce sentence on a relationship without any attempt to address the issues that lead to it, but I’ve come across many such unilateral concluders in my time. It’s not unusual to encounter those who have been abandoned by partners without a second glance and shared barely a syllable after their unexpected departure. In broader society that’s the behaviour of despots and dictators. Could you be guilty of such behaviour? If so, try to have a full and frank discussion before you make such a move.

Alternatively, it’s possible your husband’s controlling behaviour is an issue you’ve been confronting and attempting to resolve for some time. Either way, his reasons for continuing the relationship aren’t particularly persuasive. His suggestion that you’re his last hope is neither flattering nor realistic and doesn’t say much for either of you. It’s a far more selfish piece of emotional blackmail than your simply expressed desire to leave.

I’m on the fence as to what your plan of action should be. I’m not convinced by your account either and am struggling to understand why you’ve lingered so long. If having children was an ambition, you’ve been mulling it over at enormous length. After nearly two decades together, for it to be an issue only now seems disingenuous on both your parts. My instinct is that you are both in the wrong relationship, or at the very least in dire straits and in need of urgent positive action. Certainly you shouldn’t stay with someone who makes you feel controlled and parented rather than loved and supported – but for that to have taken this long to realise seems at best incongruous.

Meanwhile, on his part, if at 49 he’s only just realising you’re his best route to kids and family, then he’s either a slow learner or he’s been dawdling up until now. I can’t believe you’ve squandered 15 years simply treading water and if that’s the case I’m shocked at how little that suggests you value your lives. You don’t mention religion, so like most of us today I presume you understand that this is it, one shot, and sitting around waiting for life to change is a waste of precious moments. If you’re adamant that your best path to enhanced happiness is to be found by forging a brand new adventure then get on with it free of guilt.

At 49 your husband has the opportunity to make future babies should he so desire; you on the other hand don’t have a moment to waste. You need to move on decisively, but do try to carry the wisdom of lessons learned. Hanging around and storing resentment is a recipe for disaster. Problems in a relationship need to be aired, managed and moved on from, and not trapped in your head building up pressure. Denied the oxygen of articulation, frustrations become ultimatums and the only outcome is to finally and emphatically explode. I hope you’ve thought long, hard and honestly about what to do and that next time it doesn’t take so many years to gain clarity on what you want.

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