Will's hand on his hair made pulling back impossible, but he did stop his attention to Will's dick because honestly could not stop laughing. Will screaming 'fuck the garlic knots' was going to be seared into his memory from some time, probably bubbling to the surface at inopportune moments to make him giggle.
Deciding Will deserved something very special after garlic knot induced trauma, he flapped his hand at Will's fingers knotted in his hair. Once Will had very reluctantly let him go, Tuck said, "just trust me." Then he stuck a finger in his mouth to try to slick it up, in place of lube.
When Tuck replaced his mouth, one of his hands went back to Will's balls, but the other snuck around, and he slipped his finger gently inside, so he could press up against Will's prostate. Only then did Tuck return his attention to Will's dick.