What am I writing in the middle of a Clex & Superbat renaissance? Great question, so glad you asked.
Ot3 SuperBatLex of course, probably long ish bc I can't help myself with all these messy obsessive men
In an Au in which Lex & Bruce are childhood friends but lose touch with each other when their own personal tragedies happen. They reconnect at a party after highschool graduation... for reasons of pining mostly, they fake a sex scandal, each of them rationalizing it as doing it for their own personal strategic reasons.
Because they're both young, inexperienced with love, and emotionally useless they don't realize they have feelings for each other.
After a whirlwind summer of clubbing across Europe, sex, and not quite love declarations, Bruce leaves for some mysterious unavoidable trip he insists he has to take.
Lionel, sick to death of all the gay speculation gossip, sends Lex to the homophobia hinterlands in hopes that the good Christian Midwestern farm folks could succeed in giving Lex the shame, Metropolis and Gotham paparazzi had completely failed at.
Smallville specifically of course
On the way into town Lex hits a freshly 20 year old Clark Kent and sends them both off a bridge and into the river below, changing both their lives forever.
20 year old Clark has five years experience with his powers, he's told people and the world didn't end, he's a young adult learning about himself. He has a lot stronger opinions about his father's propensity for being both controlling and homophobic then he did when he was 15 and hopelessly isolated and sheltered.
He and Lex have immediate chemistry. Clark is old enough to know what he likes, to have gotten over his teenage longing for a false sense of safe normalcy.
His father and the patriarchal values he was raised with told him his ideal partner would be a woman who was soft, compliant, and would listen, always focused on his safety, his needs. But he was the strongest person in the world, how would that ever work? How could a relationship built on such uneven ground ever be fulfilling to either party?
No Clark had thought about it a lot, what a person would need to possess in order to survive or even thrive in a relationship with him. He knew what he found sexy and emotionally desirable, what he liked, what he needed. What they would need to be with him.
What he liked and needed was a partner with a sharp inquisitive mind, an implacable drive to achieve what they'd set their mind to, and the sort of slightly deranged self confident fearlessness that meant they wouldn't be afraid to challenge him, to be with him as a peer... even after they found out about his powers
Lex met the impossibility of their accident with a sort of sharp toothed curiosity that burned in Clark's veins.
Their relationship grew over the years, had its ups and down just like any relationship
Four years later chaos breaks out when relatively freshly minted Gotham vigilante Batman, shows up on Lex's private roof garden, in a one man hover plane, asking for Superman's help with a flood in Gotham.
Apparently Batman is Bruce Wayne? No really... And he knows Superman is Clark Kent, and and and he and Lex have history that's making them both extremely bitchy prickly defensive.
Call Clark an eternal optimist but he thinks there can be a way forward for all three of them if his boyfriend and his ex would stop trying to verbally scratch each other's eyes out...
But first there was the small problem of a huge flood to save the people of Gotham from, then he would convince Bruce and Lex to kiss and make up... and then hopefully, if destiny was on his side, and he did fundamentally believe it was, maybe he could even convince them both to kiss him
And he had so many filthy thoughts about what might happen next, if he could get these two brilliant traumatized defensive love starved men to see the light. There was more than enough of him to go around, he was powered by the sun after all. Love and sunlight were infinite resources.
Billionaires loved having resources right?
It would totally work out the way Clark envisioned.