It's always the guy you'd least suspect, isn't it?
Here, we see that it's not entirely Pa's fault. Ma shouldn't leave those things lying around. I mean, there's a time and place for everything, and that place is your nightstand or hidden in your underwear drawer. Sadly, this careless act by Ma apparently awakened a side of Pa Kent no one knew about.
Yeah, that's what I'm doing with all the friction I'm creating near my crotch! Why am I dressing like my son? No reason.
But Superboy, like the rest of us, is only too happy to overlook his father's boners. If he's anything like me, he likes to pretend that none of his ancestors were biologically capable of sexual arousal. My parents never had sex, and you can't tell me otherwise.