Sleep Asf
Means you're 'dead' on something. Or you're just completely done with everything at the moment.
Kat: Have you heard the new Drake song?
Mac: No not yet
Kat: 'You sleep asf' mac. You needa hear that new heat asp!
Mac: No not yet
Kat: 'You sleep asf' mac. You needa hear that new heat asp!