For a moment I was expecting to se him grow back and the girl say something like "how does it feel like when you're the one being played with?". But it ended wierd, basically she killed him, because eventually she's gonna pee or take a bath so... So much for that I guess.
The worst thing is that at the end you kinda feel bad for the guy, because author didn't take time to develope his "assholeness" like showing some girl in tears or even giving him a darker art.
In the end, Idk it is what it is....