Well, Atsumu was the older twin.

He's still sulky after the kiss but buries his face on the other side of Kita's neck while he and Osamu kiss.

Then, almost in unison, their free hands come up to start pushing down Kita's pants. "Commando?" Atsumu asked. "Fuck, your pussy is so hot," he murmured as he ran his finger along the slit.