Diogenes: started having public sex with the trap way before the debate even began.

From what I can tell, Augustine did not view sex itself as a sinful act, but rather viewed sexual pleasure as sinful. However, he thought that sexual passion during the process of procreation to be a "necessary evil". Of course, it still makes it odd that this meme would show him approving of traps, but I think that what the creator of this meme was going for is that Augustine was a Platonist, so he would side with Plato on this issue.
And about that "It was foul, and I loved it" quote, I'm pretty sure he was talking about a time when he stole some fruit from a garden when he was a kid.