Should i feel bad about sticking up for my sister?

Ok, so my friend wanted her friend to stay over,but my dad said no. Because he doesnt like the friend, I told him that i thought it wasnt a bad idea and he was being unfair. And then he yelled... 'Ok! But then im going out!" hes realy pissd at me now, but i just told him how i felt,coz when i was my sisters age i never had the chance to invite friends over. He left now,and i feel realy bad, im stuck in the middle.What should i do? I tried talking to him and i said... 'i just said what i felt' he replied with 'and now im doing what i wanna do' and he sped off. :'(