Trying to stay calm...

Yesterday I made this post and I am making a new one because now that I have more of what happened, I’m kind of mad. My boyfriend seems to not mention a lot of things to me. A few weeks ago he went to this carnival, called me after and didn’t mention anything. Last night while he was picking up food after work he said “I should send a Snapchat” and I said why and he said I see my friends sister who I got a job with at my job. It hit me out of no where and I later mentioned how did that all happened calmly because I never heard a single thing about it and he said he ran into her at the carnival. I told him I was frustrated because he was with her long enough for his job to come up and mentioned nothing. He flipped out on me and stopped texting me. Am I just being too sensitive?