Tali'Zorah

Tali: "I should join you."
Shepard: "What about your quest?"
Tali: "Saren must be stopped! The pilgrimage is about the greater good."
Shepard: "Sure, you could be useful."
Tali: "Thanks. You won't regret this."
Shepard: *looking at DEM HIPS* "I'm sure I won't."

(2 years and some change later)
Tali: "I'm babbling like an idiot..."
Shepard: *takes off mask*
Tali: *jumps his bones*
Shepard: "FINALLY."

DEM HIPS is a common answer to why people find Tali attractives.