I ask because my girlfriend had one of her old guy friends come up and visit a couple weeks ago. They've been friends for 15 years and she told me I had nothing to worry about. But they ended up spending the day together and he spent the night, so naturally I felt jealous. I didn't try to show it, but she could tell and I admitted it.
Now the tables have turned. I'm going to meet up with one of my old friends of about 15 years next week. I tell her the same thing that she doesn't have anything to worry about. Like I'll tell her she isn't someone I'd date and whatnot. She tells me she's not jealous and it's perfectly fine. She says she trusts me enough not to be.
So...is being jealous a good or bad thing?