It basically depends on how much you offer the lady, but there are reports that nowadays some ladies won't leave the bar with anyone, as a few make as much as 147,000 baht (source: Stickman) from only their salaries, bonuses, and lady drinks. - This is like 10x the average salary in Thailand, and, I suspect, most have a boyfriend and husband waiting at home, so why should they bother. Of course, if one offers outrageous sums, one or the other may still be tempted, which might explain the inflation in P4P prices in recent years...