Co parenting. Was i wrong?

Long story short, my ex and I have a schedule where he only has our 2 days out of the week. I contacted him and asked if he would like to take him every other weekend but he refused and said no because his gf doesn’t have her daughter on weekends. I told him to forget about it and that I’ll be contacting him whenever I needed his help & blocked him. Was I wrong for this? I honestly think that our kids come first no matter what