I've been to Siem Reap on numerous occasions, not for sex but to visit Angkor Wat. Having said that, I managed to have lots of fun in the massage places, but I saw that as a bonus.

I've also been to Pnohm Penh a few times and although I didn't find any boys in the bars, I had a great time in Hather Khmer massage, and even a bit of fun in the hotel sauna.

I was actually thinking of going to Siem Reap after Myanmar this trip but decided I'd had enough temples to last me a lifetime.