mandown, my H did the same thing. Said he wanted out, initiated intimacy with me, took off his ring two days later and left to be with the OW. They are waffling in their minds and we are paying the price. Don't read anything into her intimacy with you. With my H, it didn't mean anything, apparently, and it certainly didn't make a difference.
If I were you, I would cut off intimacy though. She might be with OM and you don't want to risk an STD. You could just say, I think we should wait to be intimate at this time. When you pull away, it pulls her toward you. Just my two cents.
I know i should be extra cautious about it. I have been doing better at pulling away, I try to do things away from the house or not be home when she gets there and such.
I haven't really initiated intamcy ya know, its her. She knows this was a HUGE thing for me prior BD. It's hard for me to turn off that part of me with her.
ME: 29 / W: 29 M: 10 (11 in March 2015) BD (ILYBNILWY): 07/26/14 S:12 / S: 7 "We need to separate" : 08/31/14 Wants to see others: 10/11/14 Separation looming