NO!!! You dont say "Hi Mom, we're just going to go upstair and screw like rabbits, we'll be missing dinner, oh and by the way, I'll help you with your homework tomorrow sis." What you say is "Hi Mom, we're just going to go upstair and screw like rabbits, we'll be missing dinner, oh and by the way, I'll help you with your homework tomorrow sis.............anyone wanna join in?" Just keep that stuff up and I guarantee you she wont be there for long.