The Saiki K manga ended. It wrapped up the storylines and gave a satisfying conclusion to the readers. Although it's over, it still holds a special place in the hearts of fans.
He could also be very kind and gentle in his reaction. Percy might not want to hurt his friends' feelings, so he'd try to let them down easy if he doesn't feel the same way. He might say something like 'You're a great friend, and I value our friendship so much' to show that he cares about them but not in that romantic way. On the other hand, if he has some hidden feelings for one of them, he could start to show more interest in return, like spending more time alone with that friend.
Naruto might initially be shocked or confused. For example, if they prank him with the fake ramen, he'd probably make a really funny face when he takes the first bite. But then he'd probably laugh it off because he has a good sense of humor.