Madagascar Suprise
You're in the middle of fukin a girl, and your friend steps in like he's been there the whole time. She doesn't even notice the switch. Then you walk up and say her name, and she explodes with confusion and rage.
She: 'You said you were gonna finish me off!' Me: 'I did. My buddy just took over.'
Girl: 'I was about to cum!' Me: 'Yeah, then my buddy showed up and ruined it.'
She: 'You were the best part of this!' Me: 'Yeah, till my buddy came in and made it worse.'