a) Of course he did.
b) If it's causing this much distress and you guys are still in BKK then this boy should be tipped his 1500 Baht per night that he stayed overnight and told that your friend will be butterflying and would like to spend time with some of the other boys. This won't offend him. It is common.

I have to say one thing, though, and it's about being a respectful and informed traveler as FlyerTalk strives to make each of us. If you're going to engage in something like this, find out ahead of time how it all works. You can search for sites which explain this in detail (and no, FlyerTalk should not be such a site). I can PM one to you if you'd like. On the respect side, if you're going to hire the bar boys, don't also call the whole thing sleazy. The bars are there as an important source of income for these boys who really are mostly working their way through school and/or sending money back to their families upcountry.

Just my $0.02 and not stated as a moderator (except for the part about FlyerTalk not being the place for a step-by-step guide to hiring prostitues legal or not).