banana equals three: When an argument gets to the point where neither side have anything new to say but are both convinced they are correct.
It is a less wussy way of saying "let's agree to disagree"
Geek #1: Hey man, you rolled twice!
Geek #2: I didn't, that roll didn't count so I rolled again and got double 6's!
Geek #1: Dude, it was a bad roll, admit it!
Geek #2: Ok, banana equals three ok?
Geek #1: Fine.