Theodore Nott had aided Longbottom? That required getting into Evan's room, getting past the wards on the wardrobe, and helping Longbottom - and getting out without making it hugely apparent. Longbottom had had quite a lip on him that time, which took strength, but Barty hadn't seen his previous condition - so he hadn't instantly known.
"I can be much more entertaining than Longbottom," Barty replied, his hands sliding up Evan's back. He wanted to make the bad go away, kiss it better or something more to make it go away.