I need a GOOD excuse to not attend a team lunch tomorrow, after spending all day "team building"?

So, tomorrow I'm going into the office for an all day team building event, but I declined dinner in the evening. I know people are going to ask why I'm not going, so just in case.. what's a good excuse?

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+1 y
EDIT - sorry, the title should say dinner, not lunch...
I need a GOOD excuse to not attend a team lunch tomorrow, after spending all day "team building"?
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