motorboat ride Share definition Flag When you are doing the sex with a girl and she gets on top and you motorboat her tits. brrrrbrrrrbrrrbrrrrpppppppp. Last night when Sally hopped on top I took her for a motorboat ride. I am pretty sure she loved it. motorboat ride by brrrrrrbrbrnrbrrbrbrrrrrr June 20, 2016 Get the motorboat ride mug.