Should I stay with my wife?

OK, my kids are almost out of the house so it will be just her and me. We get along fine- as roomates, but there is no pion or romance. Completely platonic. I am not going to go thru the rest of my life virtuous so I think I have two choices- A.) sneak around on the side and find friends to have with or B.) divorce and do it legitimately. Our society seems to have real problems with married men having with others. Most cultures don't have problems with it. AND- don't tell me to try to rekindle the romance- I've tried for the last 20 years. The harder I try the more she tries to avoid intimacy.