Just sit back...perhaps she the bet was that he would return to her and since he lost he is going to hold to his word and buy her dinner....under "different terms" would indicate to me that he is letting her know it was not romantic but as friends (which I still don't agree with...)...
I think you need to just keep your eyes open...IF things get to a point that you feel he is stepping back towards her then you will need to confront the situation (I would but that is me)... to let him know you went through this once and forgave him but the old saying..."Fool me once, shame on you...fool me twice, shame on me" applies...I know my H knows I won't do this again...he came all the way back to me...is the only time I can allow that to happen unless he can prove to me that he was criminally insane at the time...
I will keep an eye on you...just relax...things are still going good...as I said, my H "revisited"...even proclaimed his "love always" to the OW...and then that was the end of that...this might just be something that H has to "finish" with OW...to prove to himself that he is really back with you...nothing is left between him and her...
So did you ever meet her...or really confirm who she was exactly?
