person A: My sister leaves her clothes all over the living room.
person B: Oh god. The living room is shared. She should just leave the messiness in her room.
person A: I agree completely! I get so irritated and I always tell her to clean up after herself_comma_ but she seems so very lackadaisical. 
person B: How old is she?
person A: She just turned 18_comma_ so there's really no excuse.