What's the source of "shipped" in a romantic sense?
Solution 1:
TVtropes has some ideas on where the phrase could come from:
ostensibly derives from "Relationship" (though it might as well be "Worship"; in some fandoms, it's Serious Business) — was originally coined by fans of The X-Files, who were divided between "relationshippers" pushing for romance and "noromos" who would rather have No Hugging and No Kissing.
the Pokémon anime's fandom who rooted for Jessie and James (of Team Rocket) to get together and decided to call themselves "Rocketshippers"
A note on the side: Guy Deutscher: The Unfolding Of Language says one of the primary ways a language evolves is via shortening words and here it is, apparently in the 1990s "relationshipping" (or perhaps rocketshipping and worshipping, at the same time) lead to just 'shipping'.