Been quite a few tomes to Day and Night. Have only ever been offered "straight" service but their two-hour oil massage for c 800 baht was really good. No "nonsense" unfortunately, but a good competent massage. Fun and games can be had elsewhere, allegedly...
Suggest you read back through the forum and there's plently mentions of massage places that offer "extras" (allegedly). I know you will appreciate the need for discretion but sanuk starts at BKK airport (see "On The Road") and never ends.........