During the act of fellatio, the one who is sucking will suck one of the sides of the suckee's penis up and down, thus side-shafting. Side shafting may lead to what is known as the 'Ultimatum of Pleasure' which is the pre-ejaculation stage.
During a blowjob, the female may or may not side-shaft the man depending on how experienced she is or how good she wants the blowjob to be for the male.
Side-shafting can occur during a session of getting your cock sucked well.
The act of shitting and texting at the same time to get many things done at once for those busy people out there.
I had a big party to get people invited for and nothing could get in my way. So while I was on the toilet doing my business I kept at it, shtexting everyone to they could know when to show up.