This is Opal the cat.  Opal's owner was an elderly lady who recently passed away, so Opal now lives with her late owner's son and daughter-in-law.  Unbeknownst to them, Opal likes to sneak drinks from people's glasses when they aren't looking.  However, Opal is stone cold deaf and not getting away with it as much as she thinks.

 Opal The Cat Drinks from a Glass