Thou Shalt NOT Know, the 1988 (and also 2017) edition.

As we know, Michael acts like something out of the horrible romance novels and idiotic soaps that Lynn rotted her damned brain with in that he's a shitty, controlling boyfriend who feels threatened by the fact that Martha has friends and interests that aren't him. He pisses and moans and bullies and harasses Martha into giving up her friendship with Janice and Megan because he's a boring psycho who thinks that he's gotta be the bride at every funeral and the corpse at every wedding. What we lose sight of when watching him make a domineering, selfish asshole of himself is that not only does he have distinct trouble with the concept that she's a person in her own right, he has no idea who the fuck she is while his friends have known of her for years.

Since he's a shit-stupid Patterson with a severe case of "Head Up His Own Asshole", he's too damned busy worrying about the possibility of his being teased to realize what it means that Lawrence and Gordon ask him howcome he didn't tell them that Martha went to their school. If he thought about it at all, he'd probably think that she must have moved into town just to be near him because the dismal creep thinks along those lines. What he still to this day can't get through his thick fucking skull is that they were really asking "Hey, Mike!!! Howcome you didn't tell us that 'Camp Girlfriend Martha' is Martha McRae who lives on Duke Street North?! Tracey hangs out with her all the time!" because he's always going to be the dumbass who is confused and angered by the fact that an inert object he threw something at tricked him and turned into Brad Luggsworth. Knowing that they know of her older brother Stan is not something he can know because as a Pattersaint, he's kind of stupid that way.