What My Mother Doesn't Know by Sonya Sones.
Meet Sophie. She sees herself as the too-tall "Mount Everest of teenage
girls," who, along with her friends, often suffers from "lackonookie
disease." She's dating smoky, sexy Dylan, covertly chatting online with
"cybersoul"-mate Chaz, and secretly nursing a crush on sweet, geeky
Murphy. If you like this one, it has a sequel called What My Girlfriend
Icing on the Lake by Catherine Clark.