What should I do about my house mates?

I live with 3 people, 1 girl who is fab and 2 gay guys who are a couple! Thing is the gays always treat me as if they can rule my life and try to control me so we have fallen out. I am just minding my own business and getting on with it and just staying out of their way. Thing is, one of them is really really childish and keeps saying sarcastic remarks when he's with his boyfriend or when we send group emails about bills for the house etc. I have just been shutting my mouth and not said anything, should I tell him to shut his face and grow up or just ignore him and carry on as I do and not let it bother me (coz it does bother me a bit) He is 27 years old and he acts 7. Even our last house mate moved out because of him and his ways. Arrgh!