Darry and Pony had just gotten into another of their arguments, and Pony had tried to get Soda to intervene.
"Well, it's not that easy, is it, Soda?" But when I looked at Soda, I stopped. His face was white...
Soda suddenly ran out of the house, much to the shock of his brothers. Although Soda "bolted out the door" because of Darry's and Pony's bickering, it was the letter that he dropped on the floor on his way out that caused him the most pain. It was from his old girlfriend, Sandy--"Returned unopened." Darry explained that when Sandy had left for Florida, she was pregnant, but the unborn child was not Soda's. Soda still wanted to marry Sandy,
"but she just left... I guess she didn't love him like he thought she did, because it wasn't him."
Pony and Darry ran after him, and Pony finally caught up to him in the park, taking him down "in a flying tackle" that "knocked the wind out of both of us." Soda explained that he was tired of being
"the middleman in a tug o' war and I'm being split in half. You dig?"
Darry and a tearful Pony both agreed to stop fighting--for their sakes and for Soda's.
In Chapter 12, Sodapop receives a returned, unopened letter that he wrote to his girlfriend Sandy in the mail. Sodapop planned on marrying Sandy, but she felt differently and has moved to Florida. This greatly upsets Sodapop, who is on edge throughout dinner that night. During dinner, Darry begins to argue with Ponyboy about his grades. Ponyboy aggravates Darry by telling him that it doesn't make a difference what he does in school. Darry responds by yelling at Ponyboy and saying that he is living in a vacuum. While the two brothers fight, Sodapop cannot listen anymore. He tries to stop the arguing by saying, "Don't... Oh, you guys, why can't you..." (Hinton, 148). Sodapop then jumps up from the table and runs out of the house. Darry and Ponyboy end up chasing after their brother, who eventually tells them that he is sick of their fighting. Sodapop runs out of the house to avoid witnessing another one of Darry and Pony's arguments. He is already upset about Sandy, and the fighting between his brothers pushes him over the edge.
Darry and Ponyboy was fighting and making him take sides so he got sick of it and ran away but soon be caught by Pony and Darrel.