Gladio can never resist Ignis when he begs him. How could anyone? But he was the only one who got to see it, to hear it, and he can feel both pride and need swell up in him at having permission to claim him, make him his mate.

"That's it babe. You just let me do all the work for you." He purrs, and rolls his shoulders back into those growing claws, encouraging the change. Gladio on the other hand is pretty steadily human, but that will change, after all he had promised to claim him both ways. Deep in his lover now he finally moves- Pulling back, slipping out of him with the slick noise of lube and flesh as he holds his weight.

...Then a moment later his hips snap forward, entering his lover in one fast thrust to push all the way back in. His thick cock opening him up wide as he starts a pace that digs the small of Ignis' back against the kitchen counter, groaning all the while while he starts to fuck him hard and fast.

Hard, fast and claiming.