Something and simple that can be done to the both of you.
Tie the other person up, this is just so they can't move (you could make a rule that they're not allowed to move instead).
Then start edging and teasing them, get them to beg you to let them cum.
Before starting think of a time that they need to last, something like 30 minutes.
When they beg tease them some more and make sure to ask if they are sure.
As soon as they say yes, look at the time and how much longer they needed to go for every minute they were short of the time you will give them a forced orgasm. If you have a magic want then that would be a huge help.
You can decide to tell your partner the time or not, mind games
