Usually you unbutton a blazer when you sit down because it could pull or tear. However, if your blazer is loose, you may be able to keep it buttoned.
Either they want to cool down or they want to show off the same reason men unbutton their shirts.
To unbutton is a verb.
Unbutton Your Heart was created on 2010-03-12.
Unbutton, zip down, pull down their pants. Walla soft spot... I win...
your moving when your sitting down
Yes, "un-" is a prefix in the word "unbutton." It is used to indicate the reversal of the action of buttoning.
an irrational fear of sitting down. an irrational fear of sitting down.
Club Penguin has the logo of a penguin sitting down.
Sitting Down Here was created on 1999-09-27.
We Can't Stand Sitting Down was created in 2006.
If you are wearing a double-breasted jacket, it should remained buttoned. Otherwise, it is a matter of preference and comfort.
Based on the categories you put this in, were you sitting down to type? If so, quite possibly.