How would you deal with this?

Well that wrong on his part, first he is sleeping with you now your daughter. That is so many levels of messed up its not even funny. And that is a complete disrespect to you AND your daughter. I would see it as a great deal of betrayl from my daughter as well. How could she not have more of respect and discentcy for her mother. No matter how long you two have been broken up and if you still care about him or not, its just plan insulting. SO if I were you I let them both know that you are not comfortable with the whole idea, and tell that guy to get lost.

Awkward..

First off he shouldn't of done that, it may be a way of trying to get you jealous or using as some way of getting back at you! and secondly SHE shouldn't have started dating him!!

Have you spoke to her about about it? Does she know how you feel about the situation? The best thing to do is to move on, forget them and show to them that you're happy and moving on :)

Definitely not ok...depends how old you are though

SICK!!! i would out an end to that right away

If she is happy then ok.