Sparks flew when I met my girlfriend – but is she my sister?

DEAR DEIDRE: SPARKS flew when I met my new girlfriend but now I’m terrified she might be my half-sister.

I met her on a dating site and have never felt such a strong attraction to any woman. It was magnetic — and mutual.

I’m 34 and she’s 39.

We messaged for two months before we met and when she walked into the bar that first night, I knew I’d found my soulmate.

The sex was, and is, incredible.

We have so much in common too — our tastes in food, music and films, how we think about politics and religion.

Sometimes it feels uncanny — like she can read my mind. We’ll even finish each other’s sentences.

When I introduced her to my friends, they commented on how much she looks like me.

We both have sandy-coloured hair, blue eyes and long, skinny legs.

But lots of couples look a bit alike, so I didn’t take it seriously.

Then I took her to lunch at my aunt’s house and she commented how much my girlfriend looked like my late mum and grandma when they were young.

She showed me some old photo albums and she was right. The resemblance was uncanny.

The next day, my aunt rang me and told me to sit down.

She said: “I don’t know if you know this but when your mum was 17, she got pregnant and gave the baby up for adoption.”

The baby was a girl — and she’d now be 39.

I told her it was just a coincidence but it’s been preying on my mind ever since.

My girlfriend was adopted. She really could be my half-sister.

I know I should tell her and that we should get a DNA test but I’m terrified.

If she turns out to be my half-sister, people will think we are sick — and I would lose the best thing that’s ever happened to me.

What should I do?

DEIDRE SAYS: Difficult as it will be, you have to tell your girlfriend what you suspect – and you must both get a DNA test.

If she is your sister, then your relationship is incestuous and is against the law.

You wouldn’t be sick. You started this relationship in all innocence.

In fact, feeling intense attraction for a relative you did not grow up with and only met as an adult is not uncommon. It is called genetic sexual attraction.

But now that you strongly believe you might be related, you must stop sleeping together.

Before you take a test, it would be a very good idea for you to have some counselling. My support pack explains how to access it.

For reliable DNA testing, contact cellmark.co.uk (08000 362 522).

And for confidential emotional help, contact supportline.org.uk (01708 765 200).