I'd ask for the 1hour fee, not bother seeing him again and take it as a lesson.
I think it's actually unfair to ask for 6hr fee after it has happened because you are annoyed.... if I was him, I'd be thinking "you didn't tell me before it would cost me 6hrs".... it's the same as going to a hairdresser, asking for a blow dry which costs ?20 and they giving you a full colour, cut, hair mask and asking for ?300 once it's done. Would you pay the ?300 happily?
Always, always discuss the price before a booking. Even if it's social time and sex after, set the price before hand so there is no confusion. E.g., "okay so that 2hr social time at X amount and 1hr private time at X amount"
Never let a client decide when or what to pay you!! You are the boss, you set the price, you set the rules. Obviously be nice about it but you need to be upfront at all times.
And always ask for the money upfront "shall we sort paper work first... business before pleasure" etc
If things go on longer than expected that the money can be sorted when the planned time has finished.
I'm afraid, as shitty as this situation is, I feel you only have yourself to blames. And I'm sure you've learnt from it and won't allow it to happen again :-)
Xxx