In "Crush", Chloe is mad at Clark forgetting to sign them up for a conference: "Whenever Lex and Lana are around it's like the rest of us don't exist." It's notable that Lex is mentioned first and in the same context as Clark's canon love interest.
Clark tries to charm his way out; it doesn't work and Chloe walks away, mad. Pete explains that she wanted time alone with Clark with "No Lana and no Lex", once again linking them as Clark's romantic interests.
In "Blank", Chloe employs a very obvious metaphor for Clark's situation.
Clark: "I don't know why I worried so much about what people think. I don't know why I let it rule my life. I mean, you understand."
Chloe: "Yeah, but Clark, unfortunately some people in Smallville aren't as progressive as your post-amnesia tour guide."
Clark: "That's their problem, not mine!"
Chloe: "Look, I understand how eager you are to throw an impromptu coming-out party…"
What exactly are we talking about here?
In "Reckoning", Chloe reprises her line from "Blank": "After all those years of me yanking on your closet door, what's the real reason for the sudden coming-out party?"
In "Forever", Lex tells Jason that he knew he'd someday have to protect Lana from him. Jason cleverly fires back: "Not as much as you've been protecting your best friend!"
Jason is perceptive! Instantly, Lex goes into territorial mode, growling: "Clark has nothing to do with this!"
In "Heat", Desiree makes a pass at Clark and he squirms away.
He seems repelled by her, and reiterates his loyalty to Lex.
Logically, Desiree now sees him as a romantic rival and will tell Lex: "Clark is part of your past, like everyone else in this town. You don't need him…You don't need him." And Clark acts like a romantic rival, hissing back at Desiree "I'll find a way to get through to Lex!"
Poor Lex. The FBI discover his Clark-room and have some questions. It's hard not to draw a conclusion about all those wall-sized portraits of Clark. In a voice full of insinuation, the FBI agent says: "Hmmmm....You've got an entire archive devoted to the mystery of Clark Kent…." Hmmm, indeed!
Lex is embarrassed but crystal clear on one point: "Leave Clark out of this."
Lionel has cruelly used the Clex relationship to manipulate both Clark and Lex. In "Transference", he knows exactly who to threaten to get Clark to do what he wants: does he opt for Lana, Chloe, the Kents? No, he tells Clark he will kill Lex if Clark doesn't make a recording for him. Clark (as played by JG) is horrified and instantly complies.
I suspect Lionel always knew that there were deep feelings between Clark and Lex - did possessing Clark's body amplify this instinct? Could he feel that Clark was drawn to Lex in their car ride together? Mandatory Tom 'cap from Transference: Looking so pretty, being so evil!
In "Mercy", Lionel doesn't beat around the bush. He & Lex are discussing Clark, and Lionel says: "Still obsessing over him after all these years..." Oh Lionel, that's so cruel and true.
In "Lara", Lionel returns to the same theme: "Lana....now, Kara. Don't you think it's time you gave up this fixation with Clark and everyone connected with him?"
Look at Lex's face, Lionel. THAT'S NEVER GONNA HAPPEN!
Jonathan and Martha show their first sign of Clex-anxiety in "Hug" when Clark refers to Lex as his "best friend".
Immediately, an anxious glance is exchanged.
In "Zero", Martha practically makes the Clex canon with this jawdropping exchange with Clark:
Martha: "Whatever's happening to Lex is starting to affect you-"
Clark: "What do you want me to do, Mom? Cut him out of my life?!"
Martha: "No, I just want you to cool it off for a while...your father and I just don't want to see you get pulled into his problems."
Both the dialogue and Annette and Tom's performances indicate that Clark and Lex's relationship goes far beyond the platonic. It has to be HOT to cool it down!
In "Reaper", Jonathan is unhappy that Clark wants to go to a football game with Lex. It's evident he's worried about more than a football game, when he says plaintively: "He's a good kid, Lex. I don't want that to change."
Lex: "Neither do I." So much simmering beneath the surface in this scene.
Arguably, the Kents' callous attitude in "Asylum" is informed by Clark disobeying them and leaving with Lex in "Shattered."
In "Asylum", for the first time, they push him towards Lana (in quite a forceful fashion.) Anything to keep him away from Lex.
However, in "Hereafter" Martha chooses an interesting example to comfort Clark. "Think of all the people you've saved. Your Dad…and me…and Lex…"
He knows exactly how to press Lex's buttons! First question: "Now, why would a man of your stature be so interested in the comings and goings of a freshman farmboy?"
"The Comings and Goings of a Freshman Farmboy" would be a great title for a porn movie!
Bizarro tries to seduce Lex with an offer of partnership: "it's what you've always wanted...."
Since he has access to Clark's memories, Bizarro knows what Lex wants. But Lex doesn't want Bizarro, he wants Clark, and unlike Lana, he will accept no substitutes. Lex hisses back: "I'd never help you kill Clark!"
Love this guy - so direct! In "Rush", he asks: "Just what is your fascination with this boy, Lex?"
Got a couple of hours, Prof?
In Rosetta, Walden asks: What is it with you and this kid, Lex?"
Just look at them, Walden! All that mutual lust, coming off them in WAVES!
In "Labyrinth", Clark's subconscious acknowledges an important truth:
Clark: "It's Lex. He's always wanted to get me under his microscope!" Ooh, tell us more!
The doctor says that Lex is part of the fantasy world Clark has created. He's part of my fantasy world too, Doc!
(No surprise that Clark associates Lex with a phallic microscope...his Lex-dream in "Slumber" features a big, long sword.)
Even after Michael has left the show, the Clex continues! In "Eternal" Tess references Clark & Lex's tumultuous past, saying "You know, the more you love someone, the harder it is." Clark knows, lady! And, though we already knew, it's nice that Lex's love for Clark gets canonic recognition!
'caps by acampbell, HomeOfTheNutty, and SVFan.