I think there were a lot of positives in your evening with H! He was probably jealous about the "date" and figured that you were wearing the corset for him. He can't seem too interested...especially if you are about to hang out with someone else...not good for his ego I guess.
You said that he was distant...I think this could be guilt. He just spent time with OW and now he is spending time with you. It is probably good that he is distant and not just able to go from one to the other with it not affecting him at all. Does that make sense? It could have also been guilt because maybe he didn't get the nerve to break it off with OW and he had led you to believe he was going to.
No R talk could also be a good thing too. You don't want to have a R talk everytime he sees you. It is draining and stressful. If he thinks he is going to have to have a R talk everytime he sees you...he will probably start to dread seeing you or avoid seeing you. I think this happened to me and my H at one point.
Remeber to look at the positives and the baby steps!!