Like wjen somone says your a bitch just say
"Wait a minute! If I am a dog why arent I barking!" OR
"OH MAN I KNEW MY DOG WAS TRYING TO HUMP ME!"
Or when they say your self centered
"Not to be rude but I think I would die if I did not have myself in my center."
"I AM NOT SELF CENTERED! I JUST HAVE A DIESES THAT MAKES ME BETTER THAN YOU."
Or the phrase you asshole
*warning this example is being said by a person who acts like the rude person is sex talking*
"Aww thats so sweet but I dont think my parents would let me do that."
WARNING THEY WILL PROBS THINK YOU ARE WEIRD/EVEN MORE OF THE WORD THEY CALLED YOU BUT THEIR FACE EXPRESSIONS ARE HILARRIOUS!