"STFD"

            
Most are aware
ST, abbreviation for
Street or Saint
     
This is neither
         
FD is well known
with heroic moments
Fire Department
       
This is vastly different

Thank god I've never been
personally familiar with STD
Here's hoping you haven't

This is universally superior

STFU is very popular when you want
someone to shut their pie hole
Shut The Fuck Up

This is just as direct

While exchanging illicit messages
Following the receipt of this steamy sext
'I need you to STFD!'

She inquires, "What?"
Possibly thinking of STFU

My reply, 'Suck This Fucking Dick'
Her intention, "Time and place?"
A genuine FWB