Lost his job

I don't know what you mean by "how does that affect you". Are you saying he's not paying?

Go back to Court for contempt.

If he lost his job, then he can go back to the court and ask for reduction in the support based on reduced income.

It can affect you in that if he gets behind his credit rating can get ruined and it will make it more expensive for the both of you to get a loan. He needs to let the courts know what is going on and be actively searching for a job. They may allow a temporary reduction due to lost income. He needs to stay on top of this as in many states arrears acrue interest and they can take his D/L as well as his passport.