You must be this tall to enjoy this ride
Refers to either a lady's or guy's being of similar-enough height to his/her lovemaking-partner in order to engage in stand-up sex; otherwise, one of them is obliged to use a step-stool.
I appreciate any chick who is pleasant-natured and "willing", so I never bother with any "You must be this tall to enjoy this ride" height-requirement... besides, I prefer "doing it" while lying down on a comfy bed, anyway, and of course height is not ever an issue there.