C'mon man, take a hint...
Rain physically shut him up before he can deny the girlfriend misunderstanding and he didn't suspect a thing? Please.
But I like this new girl, she's tactful enough to play wingwoman for this (not)couple on a (not)date and even left before she could become third wheel. That scene where she redid Rain's hair to be more suitable for a more formal date was just heartwarming. I guess he did praise her new hairdo, although only after new girl gave him the push.