skip a beat
When you fall asleep while masturbating and wake up with your flaccid penis in your hand, either minutes or hours later.
"I thought I'd rip a beat to help me focus before I pulled my all-nighter. I didn't mean to skip a beat but I did, and I failed my exam."
skip a heart beat
When a attractive girl walks by and the guy feels a sensation in his dick that feels like skipping a heart beat
Wow look at her think I just skipped a heart beat
skip a heart beat
skip a heart beat