User blog comment:Omega natsu2/Fairy Tail's Ending/@comment-4449950-20140626081503/@comment-7418318-20140626143440

You can't really blame him for being clumsy with women. He spend his childhood first as a slave, followed by being turned into a monster by mind-manipulation, lost his memory and then ended up in prison. And when he got out, he spend his time running from the authorities and fighting a private war against Dark Guilds in the process. When was he supposed to get experience in how to treat a woman? Sure he had female companions, but they can hardly be a help in this regard. Meredy is just too young for him and Ultear was the one who turned him into a monster.

Since he never had a chance to learn how to treat women properly, it's only natural that he's clumsy. It comes with inexperience. Not that Erza is any different in this regard I think, even though for other reasons.