MSF
-Mentally sexually frustrated
-wanting sex mentally, but not physically
-usually a virgin who is feigning for sex
boy: so what chu wanna do when we chill?
(girl)anything really, but quite honestly im MSF.
boy: wha dat mean?
(girl) i mentally sexually frustrated
boy:i thought you was a virgin..
(girl) i am. in my mind i want sex badly, but physically i not feelin it as bad..
boy:lets do it! i can help ease your mind ;)

friend1:im sexually frustrated
friend2: im MSF
friend1: huh?
friend2: mentally sexually frustrated. im horny mentally
friend1: oh, im horny physically
*what have our lives come to*