mutually exclusive 

A statistical term saying the probability of two events cannot occur at the same time.

A "milf" is an example of something non mutually exclusive; as a mom occuring and being hot occuring, can indeed happen at the same time.

mutually exclusive by snapy48 January 9, 2009

Mutually Excusive 

Two statements are mutual excusives (and hence, mutually excusive) if they are each given as excuses as to why one can't take part in the other, whilst hiding one's genuine plans.

Sarah: "Sorry Dave, I can't come to the cinema with you later, because I told Louise that we'd have a girls' night in."

Then later,

Sarah: "Sorry Louise, I can't come to girls' night, I promised Dave that I'd go to the cinema with him."

Thus, "going to the cinema with Dave" and "having a girl's night in with Louise" are mutually excusive.

Mutually Excusive by JTFYM December 4, 2012