Is AUTHOR wrong in the post ? POST : On mobile so sorry about formatting

My sister and I are both very into baseball and this year we decided to splurge and buy opening tickets to the Red Sox as we don’t get to hang out often. My roommate is also very into baseball and I’m talking to him he was thinking about also getting tickets to go with his father. 

Since I was going with my sister and had invited other members of my family who ended up declining I didn’t invite him however when he brought up if I wanted to go with him I told him that I had already bought tickets to go with my sister. 

After hearing this he became snarky and passive aggressive about the whole situation. While I didn’t originally feel like the asshole, the passive aggressiveness has me feeling like I am.