Just ask if farang is ok, bring yr own condom, and be prepared for v limited English I would add: always bring your own condoms if possible. Language barriers don't prohibit punts, but I've found that Thai WGs appreciate it if their clients can speak some Thai.
"Farang OK?" is the best opening line, LOL. I've seen ads where providers list a maximum, er, condom-size, like 56. I don't know, and YMMV, but I think these providers might be not so farang-friendly, sight-unseen. Just a hunch.
It's worth knowing that a Line ID that begins with the "@" symbol is an official Line account, meaning you can add it and the app automatically pushes out a few photos and the gal's "signboard" and it's all written in Thai.
So, worth the trip out to Bang Na, you reckon?
JtB | |