Disclaimer: I don't own Supernatural.
"Dean," Castiel said. "I do not understand this." Dean looked up and Castiel was holding the cell phone the Winchester boys had gotten for him.
"It's… a phone, Cas,"
"I know that," Castiel said impatiently. "What is a 'speed dial'?"
"It's a faster way of calling people. Here, I'll put us on speed dial," Dean said, taking the phone. He was about to put his number in the number one slot but he thought better of it and put Sam's number there. Castiel nodded his thanks and disappeared.
"Hello?" Sam picked up his cell phone, mouthing 'Cas' to Dean.
"Sam? Why did you pick up Dean's phone?" Castiel asked.
"This isn't Dean's phone, Cas. This is my phone," Sam said.
"I see. My apologies," Castiel said and then he hung up.
"What'd he want?" Dean grunted when Sam stared at the phone.
"You, I think," Sam frowned. "Hello?"
"It's still me, Cas. Do you want to talk to Dean?" Sam asked.
"No thank you," Castiel said, hanging up the phone.
And that carried on for about three days. After awhile, Sam had started passing the phone to Dean whenever the caller ID had Castiel's number present.
"Cas?" Dean asked.
"Dean? This is your phone?" Castiel asked.
"No, Cas, still Sam's," Dean said. "Did you want something, Cas?" Castiel paused before answering.
"No," Then he hung up.
Dean was sitting on the porch at Bobby's house when Castiel appeared next to him, frowning and holding the phone in his hand yet again.
"What's wrong with it now, Cas?" Dean asked.
"This," Castiel said, handing Dean the phone. Dean looked at the phone, seeing the speed dial 1 pressed and Sam's number.
"This is Sam's number. You called it before, remember? In fact, you've been calling nonstop every day," Dean said and the frown on Castiel's face deepened.
"But it should not be Sam's number here. It should be yours," Castiel insisted.
"Why would it be my number? I put Sam's there,"
"It should be yours," Castiel insisted again. Dean cleared his throat nervously.
"You, uh, want me to change it,"
"Yes," Dean made the change, handing the phone back to Castiel. Castiel nodded and after hearing one beep, Dean saw the angel put the phone to his ear.
"Cas? What're you doing?"
"Calling you… There is no dial tone," Dean took Castiel's wrist and brought the phone down, pressing the talk button. Sure enough, Dean's cell phone began to ring.
"Better?" he asked dryly when he picked up.
"Much," Castiel said, with a small smile on his face.