I've found some people who act jealous and want you to be jealous are that way because they're cheaters. They may not be cheating now but they know they would given the right opportunity and they assume you're like them. So they worry about you cheating and they get upset when you don't worry about them cheating because they assume that means you don't care. It's a messed up and miserable way of thinking, and if you're not the cheating or jealous type but naive to their thinking, together you'll have a lot of conflict and confusion.