I don't think he'll come over. If he does well its something you need to talk about anyway.
to be honest from all you've said i think he'd have to know that your not comfortable with the whole situation. (but could easily be proved wrong here.
you can do it!!
when is he next seeing d? I'm sure he will have calmed down by then. in the convo i'd just keep dropping the "we need to be mature, keep a friendly r/s in front of d, and also so for d's sake maintain a good r/s with her". remember you guys got together so young, your behaviours are probably the same as they were at 17... so maybe not the best.
