people are essentially kinda gross. given that, after you find someone to shack up with and whom you can stand to be with (and they with you) for 4-8 hours a day, why would you ever want to find a second person to waste what remains of your quality by-your-self time?
i agree. maybe i'm a boring person, maybe i'm just not that multifaceted, i dunno. the honeymoon period doesn't last forever, but any idiot should know that goes for every relationship, affairs included. why get tangled in another relationship that's just going to wear thin and will also drive you insane and make your life 5 times more complicated? i like to keep things simple.