What happens if you don't pay a bondsman for someone?

My ex got arrested I bailed him out of jail and he was still making payments on the %10 to get out. 55K was his bond to get him out was 5k but the bondsman let me put 1,500 and wen he got out he was making payments to pay of the other 3,500. Now he's arrested again and me and the other co-signer are stuck paying his 3,500 but the other co-signer said he's not paying ****. Is there anything I can do? Atleast so the other co-signer has to pay too if I'm stuck paying?