Zayn smiles because he loves being the reason that he is so pleased, and that’s why he’s lowering his head and doing it again, and again. When he pulls off the third time, though, he knows that this particular time his teeth caught the head and he lets out a small huff of frustration. He licks his lips once more and takes as much as he can before he’s chocking a bit, spit coating his lips and making them a shiny mess.
Liam doesn’t know how many minutes have passed now and he doesn’t really give a shit anymore because there’s no way he’s letting Zayn stop until he’s coming. He can’t sit through an entire lecture of potions sitting next to Zayn after seeing what he is right now. As Zayn’s teeth catch on the tip he lets out a groan and smiles fondly at the huff that falls from Zayn’s lips, noting the determined look on his features. “Babe,” he sighs, as Zayn chokes slightly, “M’close, if you don’t want to I don’t.” Liam’s panting and he doesn’t know how to quite get the words out right, “Don’t have to swallow s’okay.” He manages as his hips twitch slightly.