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.
M: 43 H: 39 D: 14 Married 15 Together 16 BD: 6/2014 S: 8/2014 OW revealed 10/2014 Instigated dissolution 12/2014, in progress So over it!