I trying to remember the name of a movie i watched as a kid.

i think it was an 80's movie and all i remember about it was it was about a couple whos next door neighbours move in because i think their house blows up, the husbands brother also moves in.

theres a black cat in it and the teenager from next door keeps trying to kill, but it keeps coming back to life (he microwaves it at one point!).

The husbands sister-in-law claims shes pregnant and has this weird contraption set up in the bed so that she doesnt 'lose the baby'!

please help, its driving me round the bend not being able to remember! everyone i know thinks i made it up!!