I checked the cell phone website again today and she's texted him like 40 times today. I'm contemplating having the number blocked both texts and phone calls, but I'm worried it will make her even more mad at me and want to retreat faster. I feel like I'm paying for her to put a nail in the coffin of our marriage with this stupid text messaging crap.
If you don't want to pay for it, then don't pay for it. Cut off her phone, and tell her "I decided that I will no longer pay for a cellphone for you to use to disrespect our marriage by carrying on an affair." Blocking it is just childish.