When should a man stop giving above and beyond child support?

What is everyones opionion on a man or woman buying for their children above and beyond what they pay out in child support? I get my kids every weekend from Sun to Mon. We have joint custody but she is the custodial parent. I have over 160 over night visits per yr. I have bought them clothes supplies, school clothes, given my EX money to help her pay her rent that she shares with in live in BF. And I have dropped what I was doing to go give her money for the kids in order for them to go to the movies, bowling etc. I was at her beck n call before I met my current wife. Once I moved in with her my EX took me back to court for additional child support. A yr later when I got married she took me back to court again because her hours were cut at work and I was working alot of over time. She had the nerve to stand in court and tell the judge I do nothing for the kids. I even carrry insurance on them through my employer. Each time we went to court she won. Last weekend she learned that my child support stopped for my oldest daughter from another relationship because my daughter got married. My EX did not waste any time calling child support and asking for another hearing so she can get the money I was paying for my daughter. My current wife is on me all the time telling me to stop givng out to the kids so much and let their mother pay for things. She said this woman has her cake and is eating it too. She says every weekend my son is saying "I want" or "I need" and I immediatley get whatever for him. I pay for his hair cuts. This issue is causing alot of tension between me and my wife. Especially since once again I am being taken back to court for add'l child support. She says most men pay child support and thats it but I am taking things way out of control by buying, buying and buying. Please dont say my wife is being selfish because very few women would put up with a man who has their kids every single weekend. She has allowed me to put my kids first and her second. She is a wonderful wife, mother and an overall good woman. My EX is the gold digger and being selfish. I stepped in and raised her two kids from a previous marriage and am still very active in their life but she never appreicates anything I have done or cont to do.