Irahl sees his opening in the wake of something that he finds himself surprised (even while drunk) he hadn't needed to actually be bracing for. Vincent misses and tips his own ass over in a way that Irahl can't help but be delighted by. He needs to capitalize on something that stupid. Violence is his way of laughing at his friend.

So, he follows after him, rolling and sitting up enough to try and trap Vincent's closest arm against the mattress. His injured shoulder is stiff and mostly-useless, but he's sure it will be fine to just brace his arm downward with it to pin his friend's limb.

The room is spinning too much for him to properly sit up and get control of things, but he only needs to be slightly less clumsy than Vincent. It doesn't really matter that he doesn't have enough room to take a good swing at him. He just needs enough room to sneak in a close-range jab at his opponent's face. Just enough to make a point.

He can't help it. Vincent is just really fun to hit.