How exactly do you beat ADC Morde bot lane?

Excluding a lane swap (which I actually think might work, but in solo queue it's really rare to get a lane swap) - how do you beat a morde adc?

Yes, I'm ranting about my last game against him. I just don't understand it though. I thought going in to the game (and having played support for a morde once) that you'd beat him by harassing him relentlessly while he tried to cs early. So I did that. I got 12 free rocket autos off on him with no trade back in return. Then blitz hooked my support nautilus (who is tanky...) when morde was 2 and the rest of us were 1, I figured 12 free autos would give us enough of a lead and tried to fight it and we both nearly got killed, both used flash and I used heal.

Farm up to level 2 and 3, and there's still nothing to do against him. Base early because of the bad exchange, then proceeded to get zoned out of minions. Can't use the minion wave to avoid blitz grabs and the rest is history...

So I ask, what do you do? If morde gets full xp in a duo lane and thus will definitely outlevel (and thus outscale) you, but you can't win early fights against him even despite a huge harass lead, how do you stop him from destroying lane? At what point of the game is he weak? Once he gets a few items last hitting with abilities is a joke. Early he just last hits and ignores your harass because he's just that tanky?

Note that I'm assuming he has a tanky support. Opponents have full control over their picks, you can't count on them being dumb enough to bring a squishy support to a morde lane.