Step 1) Remember, most people do not marry virgins. Usually both parties have had previous sexual experiences. What worked for me is reminding myself we both had sexual partners before and from there I tried to push her A into that category in my mind. It worked most of the time or at least well enough that the pain wasn't utterly debilitating.
Step 2) I desensitized myself to them, and this included emotional mind movies as well not just the sexual ones. Do this by playing out the mind movies over and over again, play them again, and some more. Even when I was sick of them, I played them more. Eventually I became bored i them and they no longer stopped me in my tracks.
The caveat to this was I had to compartmentalize them in step 1 so that I had the emotional fortitude to deal with them in step 2. I've since de-compartmentalized them and am very secure in the fact that they did occur in my relationship and not prior to, but there was a definitive risk that I could be employing compartmentalization for life.
Hope this helps.
I too used the" well she even had a husband before me", and that did help some. Never had mind movies of him. It's like a curtain is over everything before "us".
I think something breaks inside us that just takes time and good memories over it to heal. No tricks work, and you may take a ride down the rabbit hole even years later. But from what I've read on SI it does get better, so I'm setting my hopes on that.
James Russell Lowell — 'Whatever you may be sure of, be sure of this, that you are dreadfully like other people.'
He chose Me!
I Won, NOT her!
She (the OW) does NOT deserve any space in my mind!
He loves Me!
He's proving his love
And then, in my mind, I punch her in the face as hard as I can.