Legal Question in Family Law in California

That depends on what the court litigation is. If you want to sue him because he divorced you, then the answer is no. If he is filing separate civil actions against you that lack merit, then you may have a cause of action against him for malicious prosecution and/ or abuse of process, and you may be entitled to have him declared a vexatious litigant.

This is something an attorney would have to review to fully advise you on, especially looking at what the prior litigation is.

Hard to say without more facts. You can not sue someone without probable cause, but an attorney would need to look at the cases on a case by case basis to make a determination if they felt the lawsuit was warranted.