1. The ghetto way to hold items on the top of a car as you transport them.
2. The reverse reach-around to fondle the female genitalia whilst getting head.
Reference to definition 1.-We didn't have any rope or twine, so we all sat in the back of the SUV and used the mexican ratchet strap to hold the mattress secure to the top of the moving vehicle.
Reference to definition 2.-I gave her the mexican ratchet strap and ran my hand down her back, around the dirt star, to fondle the poon while she was sucking on ol' dad.
An elaborated version of the sentiment is found in the phrasing: "Let me get you a straw so you can SUCK IT UP."
The proffering of a straw to aid "sucking up" abilities is generally considered more comical (read: obnoxious) than simply telling a whiner to deal.
Can be used in any situation.
*a minor chainsaw incident occurs*
Bob: Um, could you call 911 for me?
Frank: Do it yourself.
Bob: ...I don't have "hands" anymore.
Frank: How about this? I'll get you a straw so you can SUCK IT UP.