When I was younger I used to constantly get jealous and always need to know what my significant others were doing. It drove me nuts so I learned how to deal with it by realizing that I didn't have enough trust in my partner of the time. I dealt with my trust issues and subsequent relationships have been much more stable. My current wife says I get jealous of her attention (not her affection) and I realized that I was clinging to her.
It's a balance, to be sure.
"Regret for the things we did can be tempered by time; it is the regret for the things we did not do that is inconsolable." - Sydney Smith
Kyle: 27 year old male
Katie (rymmare): 25 year old female
Kids: girl: 5 years old, boy: 3 years old