I used to be a regular visitor in my naive early days of punting. Some times were good, looking back now it was because i didn't know any better. didn't know about AW or UKP.
At it worst going to butterflies is as painful as going to the dentist. shit half arsed hand jobs, and cold looks as though the girls want to get back to whatever the fuck they were doing. This is not hyperbole.
At it's best (which is rare these days) butterflies is a place to quickly shoot your load and have some quick dirty fun all for a good price. knowing that you'll be welcome back.
For £90 you get
Sex: one pop
What the old school WG's call a "full personal service"
Basically whatever you can negotiate. I'm sorry to be so harsh on this place because it was my first experience of paid sex and i felt I was treated pretty well by some of the WG's who used to work there. But if you look like a sucker they will try and charge you for everything. It'll be like amsterdam without the sculpted bodies fake tits and fake personalities, replaced with stick thin or "curvy" types.
A second pop will be £20
Expect to pay for any kinky shit including dirty talk.
If you want to go in there your best bet is to take an extra 20 and see what extras you can negotiate. be prepared to walk though as they'll try and squeeze all they can out of you.