Relationship problem reply if you relate

I’m in a 2 year relationship with my bf 15 but he is young and decided that he was ploy meaning he wants to experience more people but he told me first. At first I had a problem with it and I spoke up about it he offers to break up but he said he still loves me but I’m a little upset as he’s sleeping over at a “friends place” that he finds funny and so called hot but if they get together it’s only for two weeks and no longer but I have a problem as I get jealous and I’m upset he wants to experience other people but I get it cause we are young but if I bring up my feelings again he wants to break up what do I do?