I haven't ever had to go there, and I wouldn't, ever. I believe that if he ever cheated it would be his loss not mine.
I do have a story though. We have a radio station that had a Roses bit. Where you could have them call your mate and offer them roses to be sent to the person of their choosing. Yeah, people got busted, wasn't pretty. It was also pretty disturbing that people thought it entertainment enough to have it on a popular radio station.
