<human>: So to be clear, if she had been a different ex, I would still be weirded out, but not so scared. Husband and I dated for a while in college, back in 09. She came into the scene, and things went bad. There was definitely emotional cheating if not actual physical cheating- depending on your definition of cheating. She sat in his lap a lot, held hands, kissed him, they would make a point of hanging out when I wasn't around. I don't know a lot of the actual details of what went down back then, and I no longer care. 

I just don't want her at my wedding. My husband has made no particular expression that he wants her there, and has made a point of actively avoiding her if there was the slightest possibility their paths might cross. His groomsman is a great friend of both the ex and my husband, and I'm worried he will bring her as a +1, as she is in the area at the same time we're having our wedding. No-one has specifically told him not to, but I've been assured my my husband and a bridesmaid (who was a friend of both groomsman and husband in college) that he wouldn't do that. But without being specifically told l, I'm still worried. 

Am I being irrational? Should I just let it go? And furthermore, if she does show up, am I right to ask her to leave? What should I do?

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: worried husbands ex gf will be invited to the wedding by a groomsman who is a good friend of them both. I really dislike her, and don't want her to be there under any circumstance.