2000 Baht for each one as a tip seems generous. Offing a Cambodian boy from xxxxxxxxxx I told the mamasan he'd get 1200 Baht. She said 1000 is ok. Before anyone asks...I paid him the 1200.

And instead of asking a boy what he does try asking him what he doesn't do. Much less chance of 'language confusion' when you get back to the hotel room.