Reversing the genders in the introduction yields, "Robert's one of the smartest men[1] I know, and I thought that he was a perfect pick for the role of moderator. When we selected Robert and he said yes, he was a sexy single man. And since that time, he’s become a sexy married man, and so I wanted his lucky new spouse to stand up. So we’ve got not only a very talented, but a happy moderator.", which is only slightly weird.

Removing the obvious weird part -- "sexy" -- yields, "... When we selected Robert and he said yes, he was a single man. And since that time, he’s become a married man, and so I wanted his lucky new spouse to stand up ...", which isn't weird anymore, but somewhat of an awkward construction; you don't say "he has become a married man" in normal conversation.

If I had to rephrase that less awkwardly, I'd go with "... since we selected Robert and he said yes, he's gone and got himself married, and so I wanted his lucky new spouse to stand up ...". Maybe throw in the classic, "Let's have a round of applause for the happy couple."

Putting this all back together:

"Rebecca’s one of the smartest ladies I know, and I thought that she was a perfect pick for the role of moderator. Since we selected Rebecca and she said yes, she's gone and got herself married, and so I wanted her lucky new spouse to stand up. (Let's have a round of applause for the happy couple.) So we’ve got not only a very talented, but a happy moderator."

[1] "ladies" might be slightly off in this context, but I think it's less egregious than twisting a marriage announcement into an opportunity to call a woman sexy twice.