March was an ASSHOLE as a Riolu.

He actually made her do this in front of some enemies of his. She was only on the floor because she'd dropped a 5 Poke coin, and some kids passed by. March started ranting, Headlight played along.

Later they had this conversation:

March: Headlight...why did you do that? You didn't really have to do that!

Headlight: Because March is my boyfriend, and he would never tell Headlight to do something that was bad, of that would hurt Headlight.

March: What the fuck? No! When I say something like that, you just tell me to go fuck myself and beat the shit out of me!

Headlight: NO! Headlight would never hurt March, or let anyone hurt March! Headlight trusts March with all her heart! March hurts himself too much already.

March: You...you knew?

Headlight: Headlight knows a lot of things about March. Headlight is March's girlfriend!

After this, March learned a bit about responsibility, and was pretty fucking ashamed of himself. Of course he managed to defy this learning by taking Headlight's lunch money and using it to buy himself a pack of bubble gum the next day.
It took a lot of love (and a little medication) to turn March into the sweet, responsible guy he is today. >,>;