The instant they got into the hotel room, your wife was all over him.
When you'd confessed your fantasy to your wife -- after your third glass of wine a few days ago -- you emphasized that it was just a fantasy and that you didn't really want her to do it and you asked her to be sure to never tell anyone. But she did tell one person, and that was enough.
So now you're really not sure what to say -- and so finally, after an awkward silence, you tell her that you want her to do whatever it is that she most wants to do. She smiles and says that was what she expected and hoped you would say -- and then she says that it would probably be best if you texted him to say that she would love to go out with him and that you hope they have a wonderful time on their date.
My wife loves having sex in our master bathtub. She dated a guy that enjoyed it too and would come over every time I was out of town.