Am I wrongI wanted to attend my son's soccer game without being distracted with the care of my stepson?

My wife who was home as well and had no plans was asked to go with me so she can watch him so I could focus on my son's game. She turned it into a I don't want to spend time with her son who is with us 24/7 while my son I only spend two weeks out the month. I consider them both my son and only use the title for your understanding. She said she does not want to go because she doesn't get along with my ex. Prior to this I missed the first game because I was chasing my stepson around cause while his mom sat on the bench and watched the game. The second game was missed because of a verbal dispute between my ex and her. So this game I wanted to see without distraction from any of them.