First of all, he hates that "thing" his mother made for him, AKA the orange pullover. Second, in the original pic he said:

Ludwig: -My parents did the impossible. The only thought on WHAT they did to make me is disgusting!-

Well, since he was six, he knew how babies born.
He will understand that is a natural thing and he will not complain about it, the contrary, when he will be adult! XD

Ludwig © me