The two of you tie in the competition of reliability. He's always here. You're always not.
Sasuke thought about the differences between the two men in his life.
Itachi was so cold he burned hot. Sex with him was always intense, and amazing.
With Naruto, it was noisy, wild, and eager. Naruto was bounds of energy and sunlight. Though vampires detested the sun, Sasuke was always drawn to him.
Itachi left him unable to walk and breathless, always wanting more.
Naruto gave him a warm feeling, which was saying something as Sasuke always felt like he was inside a freezer.
Naruto made him laugh. Loved.
Itachi made him feel wanted. Intoxicated. Itachi left him wanting more in the end.