My husband's ex wife remarried and he is still paying her spousal support, is he supposed to still pay her

All states have different rules . What sort of spousal support does your husband pay... I know about 4 types:Permanent,Lump sum,Temporary and Rehabilitative.Under new laws passed in 1999, there are three different types of spousal support, and each has a different purpose. A dissolution judgment must label the award (more than one type can be ordered in the same case) and include facts that show why the award is appropriate.

For transitional support, the judge looks at what support is necessary to help the spouse get an education or training to re-enter or advance in the job market.

For compensatory support, the judge decides what will repay a spouse for a major financial or other contribution to the education, career, or earning ability of the other spouse.

For spousal maintenance, the judge considers what support is appropriate to keep a standard of living similar to what was enjoyed in the marriage. This support could be ordered for a specific time, or permanently. Many factors affect this decision.

His divorce judgment or spousal support judgment would say when spousal support ends.Spousal support does not always end when the spouse who is getting support remarries.
He must petition the court for a change.