I have 4 really close friends. I started becoming more of friends with one of them, and we eventually started distancing ourselves and paying a tad less attention to the others. We still kept in touch, a LOT. Like, we were still a group. But we just recently found out that all 3 of the other ones are in a polyamory relationship. It's not weird to me, it just makes me feel more distant from them. I'm not usually a jealous person, but I think it's jealousy. What do I do??