hi mookie! 
i went to check after reading your post
mine got bubble bubble kind of thing
but not mouldy...
(to play safe i also put it in the fridge now 
)
is there some food stuck somewhere?
for me, sometimes when food is stuck in my cavity
my gum will be painful
i will use the floss pick to clean my cavity
and then gargle... then it will be okay le
i go watch part C of JFL....
bbl~
