Set during Season 5 episode 15, "Reese's Apartment"
It was, at this point, common knowledge that Reese was an idiot.
Malcolm knew it, their family knew it, even Reese knew it, but surprisingly, and impressively, he had managed to make a decent life for himself in his new apartment. The place was clean, well-furnished, and Reese had even made them muffins. MUFFINS. So, more times than he let the others knew, Malcolm had visited Reese, and found there were many things you could do at an apartment with no adult supervision that you couldn't do at home.
Malcolm was over for the third time that week and was helping himself to Reese's dinner.
"Where'd you tell mom and dad you were this time?" Reese asked, taking some lasagna out of the oven (lasagna! made by Reese! Malcolm was already orgasming).
"I told them I was tutoring that football dumbass again," Malcolm snorted. "But I really don't think they care. After all, how big of a deal is it if they lose one more kid?"
Reese smiled, mouthing 'true' while placing the lasagna on the table in front of him. "Glad you're here though."
"Just so I can eat your food?"
"No, because my apartment means my rules," Reese smirked and leaned in to brush the tip of his nose with Malcolm's. "And tonight, you're all mine."