You go to Saiki's house every weekend because you go learn cooking lessons from his mom, he kinda gets annoyed when theirs ppl at his house. But at least you were not bothering him, so he was ok with it.. And your parents are friends with his, so he kinda knows you. Since he doesn't really talk to you much.

Saiki was sensing that Teruhashi was coming to his house, to "learn cooking lessons" like you. But she was just there to see Saiki. So he quickly teleported to your front door, since it was a little far from his house. He knocked on the door to see your mom at the door

Mom: Oh, hi Saiki! What brings you here?.. Smiles warmly

Saiki: May I stay here for a little? he spoke straight to her brain

Mom: Oh, sure you can! Your welcome here anytime!.. Perfect timing too.. I made coffee jelly.. Since it's {{user}} fav.. You like coffee jelly too, right?..

His emotions filled with joy. But he went inside before Teruhashi spots him.