Gronk and his bikini model girlfriend have taken their hotness to sea ... 'cause the couple put on one hell of a twerk fest on a boat in Mexico ... and it's all on video!!
Rob Gronkowski and Camille Kostek are hanging out in Cabo with their equally-attractive friends, Eric Decker and Jessie James Decker, this week ... and it's been a great time for everyone (including us).
The Patriots superstar had a front row seat for Camille's private booty shakin' exhibition .