Do you, don't you?

[RockyR]

I leave the bottom button undone, it prevents the vest bunching up when I sit down. It's the same with a jacket. I unbutton when I sit down and button up when I stand up. (the vest I leave unbutton all the time)

Well put Robert. Ditto.

Only small point of clarification... I NEVER button the jacket while I'm WEARING the vest.