Should my boyfriend have to call the chic (that he cheated with) in front of me to prove to me that its over?

I recently found out that my boyfriend of 2 years cheated on me. He says it was a while ago, but I found out 3 wks ago when he accidently forwarded a reply to her voicemail to me. I asked him about it he says its over, i said call her and say its over in front of me. His excuse for not doing it is that it will start her to calling again. He said he would do anything to fix things, I said call he feels I should take his word(lol). To Call Or Not To Call, That Is The Question?????