Most boys think of themselves as bar boys, working boys, or some such similar polite phraseology. I don’t ever recall seeing a profile calling themselves an escort.
They do not regard themselves as “money boys “, even though they will “perform” for a tip. I agree that you sometimes see profiles which says “MB”, but it Is quite rare.
Being called a “money boy” to his face is considered a serious insult. Ask me how I know!
Perhaps this is what he thought you were saying?
I doubt a Thai boy would understand your joke, let alone the form you produced!