Home cash game situation

[ChuckyB]

Playing a cash game with buddies last night. It's really friendly, with a tinge of seriousness (if someone's asks you what you had, you tell them to go pound sand...but with a smile.)

Heads up on the river. A third diamond comes and I was pretty sure my buddy made his flush. He pushed his last $8.50 into a $25 pot.

I had about $80. Like I would in a tournament, I pulled out $8.50, just to get a visual of what it means to me. I placed it right in front of me, without saying anything.

My buddy immediately did a big windmill big arm swing to lay his cards on the table. I screamed "No...hold on....dear god don't show me your cards...aaaagggh!" (or something like that). Before he could stop, his flush was face up on the table.

One guy thought I was committed to calling because I'd pulled my chips out, other didn't think so, and yet others had no idea.

My buddy is pretty easy to read, so I was 60-40 to fold my top two pair.

Should I have been committed to call his bet? Or what do we do in this situation?