I make it clear on my profile once in half an hour and twice in an hour. I often get the quick Cum men begging me to let them go twice in half hour and I say no. You want more you pay for more and it’s clearly written on my profile.

As many times as they can manage.
If they ask the 'how many times can I cum' question, I tell them I don't bloody know. Surely they are aware themselves how many times they can manage.
Sometimes they cum more than once, other times they don't. They are all different, some book for the hour cum within 20 minutes and cannot manage a second try. So we either chat or they tell me I can go. Some will go at it for 45 minutes, which I don't mind either as I can go for hours.