I just ask for a man, and half of them are gay. I get massages regularly in Silom, Pratunam and Ratchathewi areas. Nearly all massage venues with male employees are 'gay' to some extent- and I don't like distinguishing commercial sex venues by referring to them as 'gay' instead of 'normal.' They are sex shops, not gay shops. Recommend you get out and around a bit more on your next visit. Tipping 500B for a normal massage just sounds cuckoo- but maybe that's normal in the wonderful world of expat tourism. Out where I live- the edge of Bangkok- the hourly rate is 200B, and I usually tip 50-100B on top of that depending on how good the massage is (normal non-sexual massage, to be clear). Try one of the gay websites to get an idea of some of the venues. Not all places are the same - some have some very hunky guys, some have younger and girlie guys, some have a nice mix. Some gay massage places specify the minimum tip, which usually starts at 500bt, but they expect more.
Otherwise, even without the sex you should be tipping at least 500 (and at a gay massage place they won't be happy with that). If you do just want a massage try the Ambassador Hotel fitness centre, where you can get away with a tip of around 500bt for no sex. The massage boy getting stuck with a customer who only wants a massage is not a happy chappie.
