Although this phrase carries sexual connotations, the phrase is often used as an exclamatory one, rather than sexual. This phrase can be used in to exclaim whilst in a negative situation as well as a positive situation, however the phrase is as diverse as the work "Fuck", and can be used to suit the user's needs in many different ways.
Rafael: You got a 69 as your final grade in Algebra.
"Fuck My cock! That guy cut me off"
Trey: Dude, that girl thinks that you are hot.
Rafael: "FMC" He said coolly.
"Fuck my cock, that's a sexy car."