Bit of a strange one.
I have tried both 60 mins and 30 mins bookings and dont recall ever getting the "extras" question until there is only 15 or 20 minutes left.
Not that keen to lie there for 30+ minutes having what is often a mediocre massage before getting to the good bit so I usually only take the 30 minute option. Its cheaper too! 
When I visited, the first 30 mins was a legit massage and tbf it was a good massage at that too. But there were no CC swipes or anything despite me trying to encourage it (e.g. lifting my hips up for easy access).
On the turn over she did ask the question, forgot the girls name and don't think she's still working there but she quoted £20 HE and £40 for topless HE. I opted for topless but only after did I realise I overpaid for topless after seeing other reviews

. If I recall correctly, I was quoted £50 for B2B.
The girl was fit and young though which helped me feel less annoyed for overspending afterwards lol.
I paid £40 for 45 mins