Legal Question in Family Law in California

Not sure how he got a passport without your consent. You'll need to take that up with the passport authorities. The only thing I can think of is a forgery or lying to the authorities, which is a serious federal crime.

I do not understand why you would object to the school trip to begin with. However, even if the trip is a great idea, your ex failed to honor the obligation of working with you on determining how to handle this parenting issue. You may wish to return to court. You may also consider co parenting mediation in an effort to avoid further litigation and attorney fees.