Old flame keeping me as her back-up

I'M sick of an old flame using me for sex and cash.

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We've known each other since school and hook up whenever she finds herself single and at a loose end.

She proudly introduces me as her "back-up guy. She tells colleagues and new friends that I've always got her back.

It's true. I do but that's because I'm madly in love with her and always have been. I've never been out with anyone else be-cause she's the only one for me.

When we were 21, she said that if we weren't married to other people by the age of 26 then we'd marry each other. Yet, when 26 came around she pushed that date on to 30.

Now we're both 33 and she continues to say she'll marry me if the time comes. In other words, if no one "better" comes along.

She's in my life again after breaking up with her ex in January.