THe asking her to come with you this weekend. The following her to the car. The biting of the hand (even though it was to be funny).
Be very careful with B. You are very right that she is jealous, and you are very right that this is what happened with her. She felt the same way you did with her OM at one time...waiting for the phone call and feeling great that someone was pursuing her, etc. Then, she crossed the line. Once you cross the line it feels so hard to go back. I had said many times that God gave me a test and I failed miserably, and was a weak woman. I never thought I would do this...not in a million years. I was the good, Catholic girl that was called a "goody goody" in most of my school years, had sex ONCE before marriage, and didn't live with spouse before marriage. My H trusted me completely and never thought I would have an A. Temptation can happen to ANYONE. NOt to mention, if she thinks there is something "going on" whether there is or not, she may think "seeee...he is starting to see that he isn't as happy as he could be, a D is better for both of us."