50L or 85L for indoor people pics?

OK, I would like a fast 1.2 lens for indoor family pics. (I use a 5D)

I can't figure out what focal length to go for 50mm or 85mm?

Some will be classic head & shoulders portraits, and some just general group shots of family.

I believe the 85L is 'the better rated lens' or so most reviews say.

However, the physical size of the thing would possibly make me feel self conscious!

Can you guys help me decide?