Lucius took a step back. Rodolphus wasn't going to allow any harm to come to his brother, and Lucius supposed if he had a younger brother he'd be the same. But Rabastan wasn't a child, and wasn't going to let Lucius or his brother treat him as such. He could stand up for himself, and that was an important trait on the team; he didn't want a player always in his brother' shadow, always looking for someone else to step in. He showed strength, and determination, and against Rodolphus that was no mean feet.
"You only need to take off your shirt and trousers." Lucius told him, taking the bottle as it reached him again, taking another swallow, and then offering it out to the young man again. "It helps against the cold." He told him, before looking back to the other new team-members. "And the rest of you are to do the same! You're robes are somewhere in the Quidditch field, or in the stands, or in the changing rooms. It's up to you to find them. You have fifteen minutes, and if it takes you longer than that, well, you can come back up to the Common Room in your underwear."