The funny/ironic thing is this pairing actually DID occur (non-H, obviously) in DC Comics. The counter-balance being, while [Cassandra Cain (Batgirl III, Orphan) + Conner Kent (Superboy II)] did Canonically occur, it lasted only two (2) issues; thus why most do not know/remember it. For the short summary of the pair's comics-fling...
Part 1/2 - While vacationing with Barbara Gordon (Batgirl II, Oracle) aboard a cruise liner, Cassandra crossed paths with Conner, who was also vacationing aboard. Neither Cassandra nor Conner had met before, so the two were unaware of each other's heroic personas (& Barbara was not present to inform/reveal such). Despite that lack of information, the pair could sense the other's quality of character (beyond just physical attractiveness), and thus felt naturally drawn towards each other. The cruise liner came under attack by a large group of heavily armed pirates, spurring the three (Barbara, Cassandra, Conner) into action. In the aftermath, Cassandra and Conner realized how much more complicated their mutual attraction had become, and would entail if pursued. Nonetheless, the two shared a passionate kiss at the closing page of the issue.
Part 2/2 - In the following issue (several days later in-comics), Cassandra and Conner quietly meet-up in the early morning (literally the crack of dawn), to consider whether they wanted to pursue a romantic relationship with each other. Across the day spent together, the pair discuss their feelings, the potential benefits and complications, the reactions of their respective families (Bat-family and Super-family), fight Crime(s), halt Super-Villainy, and have a few make-out sessions along the way. Basically, a variant of the World's Finest comics-partnership between Batman and Superman. In the end, Cassandra and Conner decide not to pursue a romantic relationship further, and part as friends. However, Cassandra leaves the door open with a "friends with benefits" parting flirt. Sadly, this was never followed up with, ever again. :(