it's a competitive world. school, work, athletics. everyone has an instinct to achieve. we also analyze and think critically and sometimes critically analyze ourselves and develop self images that only exist in our mind. this sort of fantasy probably spikes adrenaline and endorphins which feel good, naturally. you just identified a pattern that isn't 'ideal' for a healthy man. but perhaps just accepting that you are a healthy minded man is a good first step. it's just part of being human. find a way to present this information to your wife in a way that might be mutually beneficial. there's probably a bunch of things you guys can do without inviting a third person, depending on her level of adventure. i understand not 'actually' wanting to invite a third person and just thinking about it. it's a simple fantasy. i've had similar ideas that have floated in my mind before.