u are C.
i always believe in beating such people at their own game.
the supervisor and their respective bosses do not know or rather
they chose not to know, as long as there's someone doing work for
them, they dont care......
so far, you are always available when the other two are not, and
their jobs are supposingly covered.
and as long as the jobs are done, no one will question the
source.
what you ought to do now is make the superior see
the problem. how? do what your colleagues are doing and probably do
it better, as in chao keng.
from the example you stated, if you foresee these colleagues of
yours will take mc at 2am, you do it before midnight.
the timing is actually not important as the objective here is to
make the superior and bosses feel the absence of
all three of you.
and only when that happens, will the superior take note when any
one of you is taking mc or ugent leave in future.
yes, what i am trying to tell you here is to spoil the
market.
but you have one problem.
prior to all these incident, you are too idle and soft-hearted to
do anything about it. only when it happens, you get frustrated.