Okay so I'm seeing a bunch of stuff with Matt being a horrible actor and worrying parents (which is hilarious) but, like, what if he just tells, for instance, Kamala's parents. "She came over to study with Kate, but they're both asleep. Is it okay if she stays the night?"
Because I feel like that would go over a lot better and also it would bring up a lot of feelings if he, say, referred to one of them as his kids.
Cue the Baby Superhero Club ("It's all Peter's fault!") calling Matt 'Mom' and him trying to act all annoyed but everyone can clearly see he's tearing up.
("IT'S THE LIGHT." Matt insists, and sniffs.
"You're blind, Matt." Peter reminds helpfully.
"SHUT UP I HAVE SOMETHING IN MY EYE."
"I thought it was the light?" Kamala says with a smirk.
"THE LIGHT GOT SOMETTHING IN MY EYE, OKAY?"
"That's not poss--" Kate is suddenly cut off.
"DON'T QUESTION ME OR YOU'RE GROUNDED."
"It's okay," Peter says, "we love you too, Mom."
Matt is totally not crying during the huge pile that is the group hug.)