Okay but imagine if Bruce was an actual bat creature stuck in a human body… he screeches and hisses at most people, his eye sight sucks ass and is very drawn to fruit. When the league starts Bruce takes one look at Clark and is like “I want him”.
He’s mixing a bunch of perfumes to make him smell perfect for Clark, making sure his cape flaps towards Clark. At some point he breaks into Clark’s house while he’s sleeping to bite down on his neck to show his interest.
And then there’s Clark who’s getting increasingly more worried about his bat friend/crush who’s been acting strange lately.
Clark's worry and confusion makes him research bats so he can understand what's going on with Bruce. He fears he may be getting sick.
So he spends hours reading about bats and finally realizes what Bruce is doing.
Bruce is ready to mate the moment he smells Clark's mixture of scents he prepared to attract the bat.