It has many meanings. It can mean hello, cool, or excited.
This phrase was developed by a man who needed something funny for his web comic.
Oh, Dave! Fackin' like a master.
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It would be fackin' like a master to play the gamecube.
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We're about to see Michael Jackson! I'm fackin' like a master at this moment.
MFL - Man fucking like is a term used to say hello from one regular to another when they walk into Alibaba Coffee and Shisha lounge. It can be used as a greeting when first walking through that entrance but also if one does something good. Like bringing in a fit girl or simply passing something to them.
Pajama casual is a term used when working from home and preparing for a video conference. All business above the waist and your pajama pants down below.