Characters with Unresolved Sexual Tension

Two people are obviously attracted to each other or have lots of tension between one another, but some element of the story is keeping them apart. This tension is frequently referred to as UST in fandom,

Some like Marceline and Bender it's played with as it varies between being resolved and unresolved, where it's unresolved with the former and resolved with the latter

For those like Boomer and Lizbeth, Lincoln and Lydia, Sora and Tai, Makoto and Kid, Sticks and Manic, Sonia and Silver, Hit-Girl and Kick Ass, Cadpig and Blaze, Sunset and Jon, and Luna and Logan it's played completely straight.