Sasuke is usually straightforward
SS shippers seem to think he was lying about his feelings or trying to hide some hidden love for Sakura but that’s just not consistent with his character.
The main thing I’m referring to is this panel:
If Sasuke really loved Sakura, he couldn’t say this so genuinely and without remorse.
Even when he’s trying to kill Naruto, he doesn’t bother to hide the fact that he’s doing so because Naruto is important:
Sasuke rarely lies and when he does, it’s obvious.
Some faces Sasuke makes when he’s failing to keep up the act include:
Let’s be realistic, that was a brutal rejection and he meant every word of it.