I agree and she does this a lot, oh whoa is me, I screwed up. If I get upset with her which I have in the past at her being flirtatious with others she immediately goes straight for sex almost as if its an aphrodisiac. She uses sex to cover up issues and has a habit of always putting things back on me.
She is very sharp, very tuned-in to her own-ed behavior.
She knows right from wrong...She is not
in a Fog of Denial.
I see serious [lack of] impulse control here...on her part.
Could this behavior [also] have led to an EA/PA?
Lack of sex for last year is a Red Flag...you know this.
Another Red Flag. fervid sexual bonding when Infidelity doubt is laid at her feet.
Not enough proof at this point to say she has cheated....and not enough proof to deny it is/has gone on.
Continue to be vigilant.
Start using VAR therapy...this therapy is for you. Place one VAR in her car and one in the place in the house where she conducts most of her phone usage. This will only expose ongoing or new illicit activity and may not bring to surface past dalliances....unless she has a confidant that she shares her feelings with.
If you assume this role....as Monsieur Snooper, you must let off the pressure and questioning. Once she feels out of the spotlight and out of Doubting Thomas's sight, she may resume her possible
Assume that she is innocent until proven the opposite. She is guilty of spending your money, this is fact.
Is she guilty of spending your sexual and emotional trust? Time will tell....or not.
Good Luck....hope it is only Green Cabbage Fever in your love garden...not Cucumber over-planting.