It does not matter one little bit what she thinks you are doing. Dont worry about how she is interpreting anything. Even if she had a camera on you 24/7 she would think whatever she wants to think. You cant battle that. By you taking any energy to worry about that is a losing battle and only you will get hurt because you are the only one who knows there is even a battle.
Trying to figure out what they are thinking is mind-reading and we ALWAYS get it wrong.
Now, this is the bad part, she is seeing you with OW so she does not have to feel guilty about seeing OM. It has NOTHING to do with you. You cant change it or stop it. Just ignore anything she says. If you defend yourself, you will push her away. Just be vague about your plans and DONT worry about it.
FB is great at telling them when you are active, but pretend they cant see that. Figure out what a good limit is for you. For example, set a firm limit of never answering her in less than 4 hours. Play on FB on your phone during that time all you want. Ignore that feature. If she says anything, just stick with the fact you were busy. Thats it.
It would be even better if you could set a limit of next day. You have to do what is comfortable for you.
Soon you really will be too busy to answer her right away.
Next, line up plans so you can quit spending time worrying about her and more time thinking about your awesome life and all the good things that you are doing with it!
Me: 42 H: 45 M: 18 yrs T: 20 yrs D: 17 D: 15 S: 12 I kicked him out 8/21/15 I will DB until March 21st 2017, that is it!