It had been 5 months since your wife was allowed to orgasm. She had agreed to cum only when you granted it to atone for her horrid affair. You figured she had cum enough with her lover.
She used to beg for it, but now she dutifully masturbates for hours. She knows that only doing as she is told will lead to your forgiveness and the orgasm she so desperately needs. The orgasm you know will never let her have. You have your own lover now, so fuck her!