Actually I went to Hanoi and Siem Reap with a traveling companion and had to be on my best behavior - not much action.
I didn't even try in Hanoi but apparently some action could be found in some of the bars found in the nicer hotels. The karaoke bars are the other option for P4P but can also be sketchy - operated by organized crime and then being overcharged for the food and drink. From what I've read, Saigon is much better.
Went to Siem Reap to see Angkor Wat but had some luck in the massage parlors. Many of the MPs are just legit massages but if you ask around you can find some on side streets that offer extras. The tuk tuk drivers are helpful and just tell them you want boom boom massage. One hour foot massages start at $3 and you can get a 4 hands oil massage for $18/hour. There are also a couple of hostess bars and some freelancers on Pub Street where the bars and restaurants are located. Khmer girls are very sweet and seem to be more curvy than their SE asian sisters. Siem Reap was very chill and worth spending a few days at if you haven't been there. Nice rooms are $30 and food/drinks are very cheap. My next trip to Cambodia will be Phnom Penh and Snookyville (beach town).
