My & Ky's Lore:
Mugs does NOT like puns MAJORITY of the time, but sometimes he makes some when he likes. (Bit of Blue/Blueberry here!) But he does enjoy playing games alone & with friends. He is also friends with Blue (Which makes SENCE if ya think about it), but mostly spends his time with Ky. (& does NOT like swearing!)
Cups however, is the chilled laid-back relaxed one of the 2. Like Classic/Sans, he likes to make puns to annoy the heck out of Mugs, but he still cares about him no matter what Mugs does to him, nor what Cups does to Mugs. (Cups & Sans could get along REAL well)
But no matter what ya do, Cups & Mugs will be brothers forever. Also apparently to Ky's lore, Ky is Mug's dad. (He says in the 50k sub special in a Q & A, true or not Idk) So yeah, I go with Ky's lore cause it's fun!
I can send you a link to Ky's channel if ya like. (Ky means Kyzer if ya know what I mean...)