When i girls bumhole is so baggy that she can fit two cocks up there. This then allows her to receive a pounding from a black and white cock, which is the act of zebra tailing.
Guy 1: 'You see that girl? Me and Reggie have smashed in her back door.'
Guy 2: 'Both of you?'
Guy 1: 'Yeah, we were Zebra Tailing'
Guy 2: 'Nice one Swaggdon'