My son started to confront with his mom about he wanted to transfer to our school district and wanted to stay with us more. There was a time his mom picked him up and he even refused to go. Honestly i felt sad for her. I first thought maybe because his dad bought him more gifts than his mom or maybe because my huzband let him play more games. But my son told us he would rather not play any video game, but stay more often with his dad.
Then we realize that it was probably because we two spent more time with the kid, and we even have a dog to play with him all the time.
Once day, my son just explained to us that he wish he had another stepfather. He said he was so lucky a child to have two moms but not two dads. He said:"sometimes it is just not that fun to stay with my mom." I understand it was not easy for his mom too and we huzband and I even felt sorry for his mom. She is a fulltime teacher. After work, maybe she is just too tired to play with him anymore.
But again, my huzband and I keep making my son understand that it hurts his mom's feeling when he is talking about staying with us or confront with his mom. So we three are working together to make best fit for our son, and his happiness. We are trying not to buy too many gifts and do not take son for too many movies so that his mom will have a chance to have fun with him.