Mate is a very British thing to say, we also use Cunt a lot. A mate can be someone you don't like, (e.g in a bar confronted with someone making ridiculous claims about cheap dank "Yer talking out yer fukkin arse mate!" and a Cunt can be someone you like, or vice-versa.
In the same bar your friend offers you another drink. Your reply could be..."Fuk aye ya daft cunt!
In both examples, Mate, and Ya daft Cunt are interchangable.
"British English 101