Helena

“Gods of Olympus.” Piper stared at Leo. “What happened to you?”
His hair was greased back. He had welding goggles on his forehead, a lipstick mark on his cheek, tattoos all over his arms, and a T-shirt that read HOT STUFF, BAD BOY, and TEAM LEO.
“Long story,” he said.”
― Rick Riordan, The Mark of Athena

“Blackjack," Percy said, "this is Piper and Jason. They're friends."
The horse nickered.
"Uh, maybe later," Percy answered.
Piper had heard that Percy could speak to horses, being the son of the horse lord Poseidon, but she'd never seen it in action.
"What does Blackjack want?" she asked.
"Donuts," Percy said. "Always donuts.”
― Rick Riordan, The Mark of Athena

“Aphrodite,” [Annabeth] said.
“Venus?” Hazel asked in amazement.
“Mom,” Piper said with no enthusiasm.
“Girls!” The goddess spread her arms like she wanted a group hug.
The three demigods did not oblige. Hazel backed into a palmetto tree.”
― Rick Riordan, The Mark of Athena

“Piper and Hazel were ready to go, but first Annabeth turned to Percy, who was leaning on the starboard rail, gazing over the bay.
Annabeth took his hand. “What are you going to do while we’re gone?”
“Jump in the harbor,” he said casually, like another kid might say, I’m going to get a snack.”
― Rick Riordan, The Mark of Athena