My boyfriend found out I cheated and wants to look through my deleted text messages.?

He went through my email & found a snippit of a convo that implied I'd cheat. My bf is aware that the guy has been a longtime friend & we've slept together many times. From the start, my bf (ex-I was ironically going to end it that night), didn't want me to talk to him(2yrs ago). The guy txted me in Feb this yr & we started again. For 1st few months, we talked about mundane things-family, TV, work. In the last couple months we hung out/had sex. All the while, I constantly deleted my msgs w/ him. It was so wrong I know. I know the pain I have brought into the relationship & how much I hurt my ex-bf. Now he is demanding to read my txts. I have deleted them but his friend is a programmer & claims he can get them. Not sure if he needs my phone or if his friend can do it without. Obviously if his friend can do it that way I can't stop it. But he is asking for me to say ok. He feels that he's got a right to know the truth & I should be the bigger person & allow him. I don't want to date him but I want to be a part of his life. If I don't say ok, he's threatened to cut me out. MOST of the msgs are just superficial-not sexually-related or graphic. Either way, I am going to hurt him. I feel that I'd rather hurt him by saying no & suffer the brunt of anger rather than freely offering access to my personal msgs. I think that's actually being the bigger person. His friends agree w/ him while mine agree w/ me. There're more details to the story but this is the basic gist. I need opinions.