If your friend and his mom are yelling at each other and you're feeling uncomfortable, just pet that furry little companion.  Chances are all the fighting is making him a little uneasy as well and he's just too shy to tell you.  So help you both out a little and pet the dog! 

If the dog bit you when you went to touch it then try another solution!  Take your phone out (chances are you already had it out anyway), and start pressing buttons and act like you have friends to text!  They won't know either way! 

In case your phone died, or the dog came back and took your phone, just stare blankly at the wall and act like you can't hear what they're arguing about.  Yes, you may look awkward, but is it really more awkward than hearing them argue about your friend leaving his trouser gravy filled socks on the kitchen table?  I think not! 

So maybe staring at the wall didn't work.  Perhaps you still heard the grueling details of the sock he calls "Betty".  Just run to the kitchen (just avoid the table) and grab a block of cheese out of the fridge and eat it.  The extreme constipation it causes will buy you at least 45 minutes in the bathroom to avoid the disturbing argument! Just make sure you avoid Betty's sister "Sally" laying in near the toilet!  

If everything else fails, just try the simplest method and leave! If you're afraid of offending your friend and his family just sneak out.  Crawl on the floor (steering clear off any more socks, of course) and maneuver your way out of the door and all the way home!  This way your friend and his family can work out their disturbing family problem and you don't have to sit through it, problem solved!