Try this
- Choose language that clearly cancels this occurrence and decide whether another date needs discussion.
- Remove automatic make-up expectations unless both want them. A cancellation should end the current obligation rather than create an invisible backlog.
A worked example
“Not tonight is enough. We can choose another time if we want.”
An invented example to adapt, not a real exchange or a script you have to follow.
Before you leave it here
Do not require a detailed reason before accepting the cancellation.