It's Nikolai who notices it; John will grant himself the freedom of his ignorance only once because he was too busy with his hand on Graves' cock to pick up on it.
Phillip Graves loves having his wrists tied up, whether to escape the binds when his partner's attention is redirected or to make a show of tugging on them and pretending to struggle.
But when his ankles are also bound, he gets whiny. Not in the feigned, brat-like attention-seeking way, but in the denied the ability to squirm in an attempt to force his own pleasure sort of way.
He can't draw a knee up on the mattress and grind his hips up against the man bracketing them with his thighs in a way that succeeds with any sort of rhythm. He can only lie there and endure.
It's well seen that Nikolai is a sick bastard; the pilot gets off on watching John torture Graves with the smallest little bounce of his hips more than he enjoys doing it himself.
