My husband says the block walls in the basement do not need to be framed for a bathroom, is this correct?

Hi, brendasp!

Do the block walls already form an enclosure that could be used as a bathroom, please?

Thanks!

I guess it all depends on the look you are going for. If you want the "rustic", "industrial", or "redneck" look, that is exposed pipes and wires with a painted block walls, then no you wouldn't have to frame the block walls.
If he is playing around with the word frame, that is he is saying that you can put furring strips on those walls and drywall or other otherwise finish them, technically that is not framing. If that is the case, hit him with the frying pan. That will "frame" his mind.