Is this illegal?:
Yes its illegal. The consequences are going to be .... you and your friend going to each house and cleaning it up. Just like when people toilet paper. A few years ago when i was a minor my brother and i went around drawing on people garage doors in chalk...long story short we got caught and had to go around and clean every single garage.

Have fun ... :)

ps...i keep reading some of these answers (HAHA)...your not going to go juvenile jail and your not going to be charged as long as its not bad words

Go be a teenager