What is the average tip for a no sex off?

On this trip to Thailand, I hope to see a guy I like at scorpion bar. I plan to off him and just hang out with him for a couple of hours. No sex.

I pLan to do the same thing with a guy that works at boys, boys, boys.

I'm wondering what the appropriate tip would be?

There won't be any groping, kissing, flirting or anything of a sexual nature going on between us.