Twenty-six years ago my son was born. I wasn't there at the time. In fact, I didn't even meet him until he was twenty one.

That would be sad, but not unusual, if I were his father. But I'm his mother.

When Tom came into our lives five years ago we didn't know he was our son. He turned up at our daughter's fifth birthday party (held in the local swimming pool) in the capacity of a lifeguard. He was a friend of a friend.

But, by the time he had given ten little girls dolphin rides all around the pool for an hour, organised ten lots of party plates, helped with presents, then come home with us and eaten vast quantities of spaghetti bolognaise, he was not only a friend but a member of the family.

He liked us as much as we liked him. His own family was chaotic and he loved the ordered structure and discipline of our home. He idolised my husband and adored the girls.

It became automatic to invite him to everything and our neighbours and friends have become used to him as a fixture, but it was still a shock when one of the neighbours asked, in all innocence, "So, is Tom your son from a previous marriage then?"

Well, yes, the colouring's right, the nose is bang on. So yes, he could easily be my son. We began to joke about it a bit. When I take him shopping or we're out as a family, it's just easier to introduce him that way.

Sadly, at Christmas, his own family, always dysfunctional, stopped functioning at all as far as he was concerned and if home is the place you can always go back to and they can't throw you out, then although he'd moved out to go to university and then to a job, he was essentially homeless.

But not anymore. He's asked me if I can be his real mum (I think the job involves doing his washing and mending when he comes home, baking him cakes and allowing him to empty the fridge and probably slipping him the odd fifty quid when he runs short) and of course I've said yes. The first thing my husband said on hearing the news was "I'd better clear out the spare room for him then, so he's always got a place to stay," and my daughters want to sign a bit of paper so they have an official and legal big brother.

I don't know if you can adopt someone when they're twenty six, especially when they have biological parents still living, and we've probably got some stuff to sort through to make sure it works for the long term. But he's chosen us as his family and we've chosen him as our son. We'll make it work between us.

Proof that you can choose your friends and sometimes you can choose your family too.

Mary

A Moodscope member.