Regulus looked from Lucius, whom he was seeing as some sort of shining beacon of hope for redemption, then turned when the Lestrages returned. Rodolphus looking as smug a prat as ever, and Rabastan... he appeared to be annoyed at something, or someone. Regulus was trying, with great difficulty to read the who or why of this then heard Lucius suggest that Rodolphus escort him back to the common room. Regulus' mood clouded accordingly and perhaps a bit of it was jealousy mixed with a perceived slight on his abilities to handle himself caused him to pull away from Lucius.
"Sod off! All of you!" he spat. "I may be the younger of my family's children but I certainly don't need a bloody nanny to look after me!" he said and started across the dark field back in the direction of the castle. Before he got too far, he turned, pointed his wand and commanded, "Accio whisky!" and the bottle flew out of one hand and into his with a deadly accuracy. Regulus gave a final look at the gathered group, and then turned and with a proud posture but a less than steady gait, left the field, destination unclear.