Second Best....

Last summer right before my boyfriend was about to go to college (we were about to become long distant) he told me we should “see other people” and if we don’t then we can hangout when he comes home on breaks. At the time i had another guy friend i would frequently hangout with along with my female best friend. Because my boyfriend was planning on moving on I was considering pursuing my other guy friend. While that never happened because once my boyfriend got to school he decided that everything he said was dumb and he wanted to continue dating it still hurts my feelings. I can’t help but feel as though the only reason we are still dating is because he didn’t find someone at college, making me a second best. Now, although it’s almost a year later i wanted to invite that other guy to my graduation party but wanted to ask my boyfriend first. he said that he “didn’t want the guy i was going to cheat on him with there.” However, I wasn’t going to cheat!!! l was told to see other people BY HIM!!!This is an ongoing argument between the two of us and i just want to know how to resolve it, or if i am in the wrong with my feelings.