Break up with him.
Call the police.
Get rid of him!
just like you get rid of anyone else... you use a gun
Introduce yourself to his wife.
Sounds like he/she doesn't like your boyfriend or is afraid of him. Has your boyfriend ever mistreated the cat? If so, get rid of the boyfriend asap!
get rid of the boyfriend and have two guys with benifits. then your not cheating on anyone
get rid of it
Get rid of him.... and fast.
Change the locks
call the cops.
It means, at minimum, you should get rid of that boyfriend.