Scope creep works because every added piece sounds small by itself. The trap is not one request. The trap is the slow conversion of your time into an unspoken obligation.
Name the new ask as new
A toxic boss often speaks as if the expansion is already included. Do not argue about whether you are helpful. Reset the frame: this is a new request, with new scope and timing.
The cleanest move is to separate the original commitment from the additional work.
That is beyond the original ask. I can discuss it as a separate request.
I can finish the summary today. The full report needs a separate timeline.
Before I add that, we need to reset the scope and priority.
Do not prove your loyalty
The phrase team player is often used to turn a planning problem into a character test. Once you start proving loyalty, the work request disappears and your identity goes on trial.
Answer the logistics. Leave your character out of it.
I am committed to the work. I am not available this weekend.
I can help during working hours Monday.
This timeline does not work for me. What should move to make room for it?
Ask the priority question
If everything is urgent, nothing is managed. The priority question forces the other person to choose instead of letting the cost disappear into your private life.
Which current priority should I pause for this?
What deadline is moving if this becomes first?
I can do A or B by tomorrow, not both.
