If a 14 year old girl gives a 14 year old guy a nipple cripple, is it inappropriate for him to give one back?

Well, in summary, I'm the 14 year old guy and this happened to me today (the girl is my twin sister). I got into trouble even though she started it. I think this is so unfair. Just cos she's got boobies my dad says that makes it worse! Now I have to spend the rest of the evening in my room and she gets no punishment. Grrrrrrr!!