There is a time for force and a time for persuasion, sometimes there's overlap, but in this case and instance the latter is what is required for what he is after. He cannot play his hand too early, too loosely, or any seeds he attempts to plant will only find barren soil.

That Noctis whimpers into the kiss, shivers as he does to his touch, and even moves to grope at Barnabas' own ass in an attempt to bring him closer is a good sign. Even if he's aiming to assert his own Dominance and control here, this still shows him that this is working, that Noctis wants this. That his desires are as plain as the growing wet spot on his thigh. His thigh which he presses and flexes against him more as he holds his place despite Noctis attempting to bid him nearer, just allowing him to grind against it.

In fact, he seems keen to keep this up, to tease and tantalize Noctis, but not give him much else. Simply content to drive him wild with enough stimulation to keep him present—locked in the moment, incapable of escaping it—but not quite enough to get off or progress things further. If he cannot command him directly, then he will wear his will down by other means. He is a dangerously patient man, and keenly adept at ignoring his own needs even as they press aggressively against the front of his pants.

Breaking the kiss, he capture's Noctis' lower one between his teeth with pressure that threatens to be more than what it presently is as he pulls on it—stopping before it would get painful as he goes in to kiss him again, his tongue quick to follow the locking of lips. His hand, however, still groping that breast, his thumb rubbing over the pert nipple, teasing it with the pad of it over its stiffened peak.