Rabastan had already been upstairs to change and help Regulus to bed. He hoped the other boy would come down to join them in due time. His anger at Regulus's earlier antics on the Quidditch pitch had abated and he was left just hoping that his friend would put in an appearance so he'd have someone to talk to for the rest of the evening.
Stepping into the Common Room he glanced around, lip curling slightly as he saw how freely the drinks seemed to be flowing. Apparently Lucius had less control over the rest of the house then he imagined he did. He found a corner that was mercifully free of other students and waited there for either Regulus to appear or for Lucius to hurry up and announce the new team members so he could go to bed.