I personally would not allow my husband to visit Bangkok, Thailand, with his friends. It’s not that I don’t trust him, I don’t trust his friends. Seriously though, Bangkok is well known for its sex tourism. Prostitution is part of the culture and prostitutes can be found in many different places not just the traditional brothels and massage parlors, but also bars and even karaoke clubs.
I’ve also read that over a million Thais are currently living with HIV/AIDS. I’m sure there are other reasons to visit but I would first want to know what they plan to see and do and why they chose Bangkok over some other place.