Some of my friends call their friend, their wife or sister. Do you know anyone who does this?

Yes some girls I knew from school refer to each other as 'wifey' and some are 'married' to each other on FB.

Yes, a girl I know does this - she's a moron.

The "married to" thing is not uncommon among my younger (unmarried) fb friends.

Yep, several people. I believe it's quite common.

A friend of mine has a "wifey" - someone she worked with years ago.

Yes one of my moronic friends has a wifey to go out getting drunk with and ending up sleeping around getting preggers.

Yeah I have many, mainly women and The Gays.

No and I also dont friend zone people or mug them off. The choice of language seems odd to me not I don't accept language and new words appear all the time. The problem is they use the same words in different context to mean different things.

Mug them off is it :- not talking to someone, having a fight with some one, dumping a partner. I have heard it used in all this context and people just nod as if they understood while I am left wondering what they actually talking about it.

I know a gay man whose Facebook status claims to be in a relationship with a close female friend. It's just a fun thing people do.