screw yourself

It means you're being/doing/saying something unpleasant and you need to go away and get lost. A person who is upset at someone else's actions tells them to "Screw yourself". They could also say Fuck yourself instead but Screw is the cleaner version. Q: How does "Screw yourself" or it's equivalent "Fuck yourself/Piss off" mean 'get lost'? A: 'Screw yourself' implies before this bad transaction between 2 parties. The analogy in this sexual metaphor is that it WAS a mutual and pleasant affair between the 2 parties BUT now the offending party can do it all alone (Masturbate) because they're no longer welcome in each others company. Ergo, screw yourself cuz I ain't fuckin' witchu no more