If Percy admitted it to himself, he was slightly nervous about how this was about to go. Not that Neville Longbottom particularly intimidated him (if anything, Hannah was the one you wanted to watch out for), but he was acutely aware that he'd been sitting on this information for an unacceptably long time.
It was not that he thought Neville shouldn't know about Alice's involvement with Potter's Army. More that he wasn't sure the other man would be much concerned by the news. He had, after all, led Dumbledore's Army in his own final year of school. It was entirely possible he already knew and fully endorsed his daughter's extra-curricular activities.
After weeks of wavering one way and then the other - and without Audrey's advice to help him - he'd finally decided that he really ought to say something, if only because Alice was getting herself involved with people like the Bittel girl now.
And that was how Percy found himself walking up the Longbottom's garden path, carefully avoiding the more exotic plants, and knocking at their door.