The phrase can be used: 1. to express extreme frustration; 2. in complete sarcasm to another who may be of general inconvenience to you; 3. with supreme elation or joyfulness, contradicting its meaning in a symphony of ironic vulgarity.
It can be used by either gender, despite its reference to the clitoris.
“Shit on my clit!”
“Yeah, asshole, keep shittin’ on my clit.”
“Shhhitttt on my clit!”