Try this
- Agree on the main activity and a rough duration before adding surprises or extra guests.
- Make any extension optional at the end of the planned time. A quiet goodbye can remain part of a successful occasion.
A worked example
“Let’s open our cards and talk for half an hour. If we both feel like staying longer, we can decide then.”
An invented example to adapt, not a real exchange or a script you have to follow.
Before you leave it here
Do not make ending on time sound like rejecting the celebration. If you want more time, ask for another occasion rather than withdrawing the agreed exit.