Nonhuman expressions of affection are great. Purring. Exposing weak points as a show of trust. Head bonks. Preening and chewing. Nuzzling. Biting. Intertwining tails. Feeding each other. Little chuffs, chatters, beeps and squeaks. Fluffing up of feathers, fur or other things. Dancing to impress. Cleaning their fur, scales, feathers or skin. Sharing body heat. Ears pointing toward those you care about to show your full attention is on them. Slow blinking.
[VD: A Magnus Archives animation done in orange and teal titled "Pusryčiai" (meaning: "breakfast"). Mellow music plays as Martin cracks two eggs into a frying pan. He turns away to throw the shells while the pan sizzles, and when he returns with a spatula, a "boom" sound effect plays as Martin recoils with comic disgust.
The egg yolks have been replaced by human eyeballs. Martin stares at them for a moment. He then pokes at the egg with the spatula, producing a squelching sound, and one of the eyes blinks with another gross wet sound. Martin goes from disgusted to comically sad and disappointed, and he fades away before the setting does. The video ends on the words "darė Skaistė" (meaning: made by Skaistė) and a quick shot of an eyeball. End VD]
ty @princess-of-purple-prose for the description, i edited it a bit too.