Alex McAllister is the father of Natalie and is a single parent. He was introduced early and was very close to catching Satan, but Natalie prevented the secret from escaping by creating a persona for Satan to use last minute. Trusting Natalie, he now firmly believes his daughter is tutoring a freshman from her school.
From what we've seen, Natalie and Alex have a very good parent-child bond, although he is gullible to an extent as Nat manages to fool him into believing Satan is "Stan", even if there was apparent evidence to doubt her.
He treats "Stan" very well and invited him to stay over for dinner when they first met. It is yet unknown how he will react to realizing who "Stan" actually is, but fans have theorized about a very wide range of reactions (detailed below).
No interaction between them has yet been depicted in-canon but it's safe to say that they have good relation because of Michael's friendship with his daughter.
Fans have made up situations about Alex's realization about Stan go from him being revealed a secret satanist to a religious fanatic. Some have proposed the idea of Alex welcoming the Lord of Hell as an official family member and some about Alex trying his best to separate his daughter from Satan.
- Alex is often the target of puns; for example, when he is paired with Satan they're most commonly called Ditto (because DadTan sounds like that).
- Alex has made the Lamp character a very popular one as fans adore Dad/Lamp pairing, mainly for its humorous value.
- His wife died when his daughter was very young.
- Due to his wife dying, he became alcohol dependent. Leaving young Natalie and young Max to take care of themselves.