Board Thread:False Info and Speculative Discussion/@comment-26781694-20160309171151/@comment-4091815-20160518195809

As I also stated earlier - It's hard to quantify Parrish's status because of his duel nature.

The twins were actively refused entry to the pack by Scott. He said no. They still allied themselves with the pack but Scott wouldn't let them join because other pack members were against it (Isaac and Stiles).

Mason was allowed to meet with the pack, he actively helped the pack in Season 4 (as an ally) and actively planned and worked with the pack in Season 5. He's as much pack now as any of the other humans were at the end of Season 2 when Derek said that Scott already had his pack.