Let's say that both girls have been shopping and both have some stuff to carry (purses, bags, drinks, etc). Girl #2 offers to help girl #1, even though they're both pretty similarly weighed down. Girl #1 accepts the help and hands girl #2 one bag. As time elapses, that one bag evolves into the majority of girl #1's stuff, except for a few little things. Girl #2 is fine with it; she's a buff chick; but after a while it gets pretty heavy.
Girl #2 tentatively asks if girl #1 can take a few things back. Girl #1 gives her a withering look, but takes two bags. In a little bit, girl #1 whines that they're too heavy, and girl #2 (feeling guilty) immediately loads them on.
Pretty soon, girl #2 can't keep up. Girl #1 is irritated and runs ahead to meet some other friends, leaving girl #2 with all the baggage. Girl #1 eventually comes sprinting back and girl #2 is ecstatic; she's hurt, naturally, when she finds out that all girl #1 wants is her iPod out of her jacket pocket (which girl #2 is carrying) and that when she finds it, she leaves again.
So it's no surprise when girl #2 puts her foot down, right? She's tired, blast it all, and girl #1 is perfectly capable of carrying her own crap. But girl #1 throws a fit. She accuses girl #2 of being needy and not caring about their friendship. Girl #2 throws out the fact that girl #1 hasn't done a bloody thing, while girl #2 has been doing all the work. Girl #1 snaps that she carried two of her bags that one time, remember? Girl #2 wearily concurs, and the quarrel is over.
Girl #1 turns around to go back to her other friends, notices that they've left, and then in a falsely sweet manner turns around and offers to buy girl #2 lunch and then shop some more. Girl #2 is disgusted, for she hasn't missed a detail of what just happened.
She resists the urge to drop girl #1's crap in the fountain and instead hands it back to girl #1wordlessly, then finishes her shopping alone.
Note from the author: This is not a true story in the literal sense.