Sidon x Link headcanons!
Because the Zora use sleeping pools, Prince Sidon had a Hylian bed placed in his room for when Link visited. The thing had to be custom built for Sidon's size and weight and is fitted with soft, waterproof sheets and pillows but Sidon often uses it even when Link is not there with him.
Link has no idea what Zora courting looks like so when Sidon begins fishing for him and attempting to hand craft weapons just for the hero, Link is confused but flattered.
Link is a terrible swimmer. He can swim just enough to not die and he can hold his breath underwater but that's about it. However, he loves to show off for Sidon so he's often trying to impress him with his "skills". Sidon applauds him but makes him promise not to go into too deep water (or dive off Shatterback Point... again).
It is Zora tradition to gift a sapphire set in a piece of silver jewelry (thanks to a certain princess of a long time past) as a marriage proposal. Link has no idea what the gift means and happily accepts the piece of jewelry. Link only realizes the meaning when Sidon begins talking about wedding plans.
Kissing is not something the Zora do; instead, they nuzzle their crests. Link is happy to teach the prince how to kiss, but he often nuzzles and pets Sidon's crest. He likes the way it makes his head tail wag.
(If you headcanon Link as mute or selectively mute like I do, Sidon already knew the signs. The Zora often use them when underwater and/or hunting.)
