3 letter word

for someone who has never studied or lived outside of japan, zume
has awesome- no stupendous english ability. his motivation is
bewildering and his moxie is enviable. of course in the last year of
knowing me he has been challenged some what to get a grip on a twisted
contorted style of english language. i often hold back with the
colloquialisms and the thick raw slang, but he's pretty quick and whips
out a good 'jeezus christ this place 'as gone to the dogs' (half of
which he already knew himself) often his knowledge and questions about
'my' native language are beyond me...

last night i went downstairs to find him mucking around on the
mac, he was showing me some stuff he thought was pretty cool...and i
noticed a small dictionary pop up in the top corner as i looked closer
at the word in the box i giggled as i saw what he had been searching
for - there were the three letters R-A-T

later i giggled again as i remembered that earlier that day
on the escalators up to tower records i had called him a 'rat
bag'