Maybe some headcanons on how cryptid ut uf sf sans and us pap show affection to their s/o
C-UT Sans: Not very affectionate, you would think. He always seems so distant, the way he sits around, staring off into space and daydreaming, or just talking to you in this nonchalant voice.
But he is such a cuddle bug. The moment he actually develops feelings for you, he will just sneak onto your lap, hug you around the middle and stay like that. He is content now.
C-UF Sans: Spikey, dirt-boy isn’t to keen on cuddling, the risk of harming you is too big for him to actually enjoy it.
But..he likes making small presents for you. He is rather crafty with clay, so he often makes small clay figurines for you, animals, plants, people.
C-SF Sans: Brings you cool stones he finds in the swamp. Look! This one is shaped like a dog! Oh, oh, oh, this one is shaped like a fish. ANd this one…
Shaped like a rock. But still cool.
Also nose nuzzling, even though…he doesn’t really have a nose.
C-US Papyrus: He is lazy, and not really into doing things in general. But if he likes you, he will offer you some of his sweets from the stash in his pockets.
And if he really likes you, well, then he will make some sweets for you. No, not his honey. He knows how to make fragile, beautiful figurines out of sugar.
He also loves to drape over you and cover you with his sticky self. Enjoy.