Tim: Happy birthday mate!
Jim: Thanks. :-)
Jim: You coming to the party?
Tim: I'd love to but I have responsibilities.. Meh!
Jim: Stuck babysitting your little sister again?
Tim: How did you guess? LOL
Jim: Cause you're always bailing out on events lately and it is always your little sister... 
Tim: Hehe... 
Tim: If I don't babysit her my parents will kill me.
Jim: How old is she again? 12?
Tim: 13
Jim: Old enough to stay home alone then.
Tim: That's not what my folks think or say.
Jim: But your folks are dicks.
Tim: Yeah I know. I can't wait to finally have enough cash to move out of home.
Jim: Do it!
Jim: It's not easy but at least you have your freedom.
Tim: I don't have the money though.
Jim: You can always move in with us.
It's Jim's birthday. Tim is not coming to the party as he has to babysit hist 13-year-old little sister. Tim is missing events lately, because he has to do this. Tim's parents don't think Tim's sister is old enough to stay home alone. Tim would move out, but doesn't have the money.