Funerals and Reunions

http://marriedmansexlife.com/2012/08/new-rule-funerals-and-reunions/

If there’s a funeral, and there’s out of state travel involved, either you both go, or you both stay home. Same deal with reunions too I’d say. You both go or you both stay home.

Chalk it up as a kind of "trust, but verify". If she really wants to cheat, she'll find a way. It's just the way the world works. However, if you tag along, simply by being present you can prevent old flames form rekindling in the first place. An ounce of prevention is worth more than pound of cure.