A reference to the character Sidon in The Legend of Zelda: Breath of the Wild. He says things like "You can do it! Stay strong!" to Link (hence 'supportive'). He is the prince of the Zora race, who are designed after sharks (hence 'shark'). Due to his admiration for Link, many in the BotW community have taken to shipping the two characters (hence he is Link's/the player's 'boyfriend').
The act of clicking the like button on someone's new profile picture or status because they're your girlfriend/boyfriend/best mate and you're obliged to, or more commonly because you know the person's post will just be ignored otherwise and you feel kind of sorry for them.
A newcomer vegan who supports those who don't understand what a real diet is and may fall flat later on in life, however by dedication they can become a full-time vegan.