child support

[Katey]

My uncle signed away all custodial rights to his 2 boys when he was a teenager or young adult. He said he agreed to pay child support. This has been about 15 years asgo. He has paid support directly to his ex, with cash, a place to live, and other significant means of survival. Recently she kicked him out of their home, and told him to stay away from their teenager that remains in the home. The oldest boy has turned 18 and moved out. What are his rights and what rights does my 16 year old cousin have? Thank you Katey