So basically person one posts that they want or need 'x' and the next individual posts why they can't have or obtain 'x'. The exchanges are between poster one and poster two. Poster three has to make a new 'x' for the next person to make an excuse. So no long winded conversation threads!
p1: "I want a burger"
p2: "I don't have a grill"
p3: "Give me a lift to the library"
p4: "My plane doesn't work, you'll have to walk"
Your demand or excuse can be as ludicrous as possible, (willing to bet you know someone offline who will give such excuses lol).
Have fun. I'll start:
Can I borrow a beach ball for the pool?