Most of the time, the people who use the words often don't know the actual meaning themselves but use it anyway understanding the fact that the words are used to describe a person or situation in a bad way. e.g: "ur a fukn shit cunt"
There are also other ridiculous definitions within this site describing it literally but in the sense of having sexual intercourse, as well as somehow integrating homosexuality into the words definition.
Example of an idiot using "shit cunt":
1)"Fukn ya ura fukn shit cunt bra"
2)"Get in 'ere ya cunt"
3)"Fukn cunts dese dayss brraa"
4)"I wazz down at centrelink bra and dese fukn shit cunts cuma long and fukn 'ell, SMashed the dickhead"
5)"YA SHIT CUNT BRA!!"
6)"ahahaha ya shit ya cunt!!"
Needn't say no more.
Although examples 2 and 3 do not use the words "shit cunt" it does however, relate to the idiots who use it.