When you choose to engage in sex acts with minors in foreign nations, even if your tour guide says "it's cool", you risk facing criminal charges in the U.S.

Your "happy ending", if delivered by a child (a person under age 18), is an act of sexual conduct. But at least as of yet, you've given us no reason to believe that the U.S. authorities are aware of your proclivities.

There's no nation in SE Asia in which sex acts are part of a massage, unless you're going to a place that performs sex acts under the guise of a massage. There's no massage parlor in SE Asia that is structured to offer legitimate massages but then throws in sex acts as "freebies".