OC...like I mentioned to you before...my H kept some contact that I didn't know about at the time...but in the big picture of things I think it was to make sure she was ok...you know that whole "Knight in shining armor" thing...they came to their rescue and now they need to make sure they didn't abandon them...
As long as things are going okay with you both...and you can see little steps here and there...I would leave the issue of OW completely alone...I know it nags at you...believe me, I still wonder at times...but I know in my heart now when H says he loves me that he does...and I have no worries that SHE means anything to him anymore...in fact the few times I have mentioned her name he will say something like "who?"...as if he is truly not even aware of her existance anymore...
So hang tough...you can bet those guys at dinner will have an impact on H...they will be telling him what a lucky guy he is...he will eventually have to admit to himself he is...maybe not to you verbally...but you will sense it...trust me!