There was on place I left where the company was doing OK, but there were a lot of red flags on exercising options, so I let them expire. Someone asked why I didn't just exercise some for fun. I didn't want to have to do the taxes. Not pay the taxes, I mean fill out the forms.
I've exercised options a couple times and never filled out any forms until I've sold. Was I supposed to? They never sent me any, so I didn't bother. Most private companies are pretty sloppy about handling their options. You send them a check to exercise and they'll note it in a spreadsheet. That's basically it.
