Chess old man.. The head on that pint of Quinness doesn't quite look up to standard ?? Did you pour it at the correct volume ??
Hey, wait just a minute here!! Upon closer examination, it appears someone may have helped themself to a quick nip !!
My final question to you sir, why weren't the rest of us invited over ???
PS: You do get points for using the correct glass :-)

LFE ! The rest is just details..