Free.
Had a booking, and en route to the sp home, I received a text asking me to pick up rubbers. The nearest place was off my route, and of course there was fucking queue - by the time I got to her place, I had 25 mins of the booked 60 left!!
She said she had bookings later so couldn't offer me a longer time. As I was about to get all pissy, she then said 'but as it was my fault, and you've done me a favour, you can have a free bj'
There's was no way I could turn that down, and I soon forgot I'd been messed around...