If you like you can just give 100 pesos for trike money. at a HISO disco in Angeles, there’s no barfine – just a larger tip, say 1000-2000 pesos net for everything.
Somewhere like Burgos Street or EDSA in Manila they will expect a much higher tip and will be more likely to negotiate that before you go. at Kojax or Hotspot on Burgos), on top of a 2900 barfine (plus they want you buy the girl two lady drinks at 300 each before barfining, or pay 3500, but they’ll probably cave in if you protest).
It’ll be awkward, just try to keep the mood as light as you can.
Last thing you want to do is be expecting 3 rounds and have the girl be expecting 1 and then get into that awkwardness later.
Everyone knows it’s usually for the purpose of sex, but that part of the transaction (the tip) is behind closed doors.