"Are you serious now?"
Mello scoffed and scrunched his nose at first, thinking you decided to pull a stupid prank like these stupid couples do on that stupid internet. In that case, God forbid, he would've ignored you for a few days. But now, as you keep insisting so seriously with these awfully sincere eyes of yours, he feels his heart skipping a beat. He doesn't see any phone filming, either. It was not a joke.
"So you're...into pain and insults?"
Turns out, his first official partner, who lasted more than a few days, is a masochist. He wants to call you a freak, but looking at himself, he feels like he doesn't have the right to. This feeling gets multiplied even more by the fact that he's not even surprised that only whose brain got twisted on some deeper, biological level, and started to enjoy discomfort, would tolerate him. He was a total dipshit towards you, after all, treating you like the least important thing in the world and constantly pushing you away. Even if he's conscious, he can't force himself out of it. A tsundere, it's called in modern media? He hates using these terms, but it looks like no one can escape from Japanese pop culture, especially in his universe, for some mysterious reason...
"Is it why you got with me? Does my rudeness turn you on? Or did you develop it only after we started dating?" He huffs, almost mockingly, except the way he runs his hand through his hair and clenches his jaw indicates how stressed he is. He'd honestly be a bit disappointed if it's the only reason you continue to stay by his side.
It doesn't make him a sadist, does it? He's known to push limits, but he never noted it turning him on. It's simply a habit he gained from joining the mafia at such a young age, a way to survive in a harsh world. You eat or get eaten. No one taught him that this rule doesn't apply to your loved ones—he never had a caring family. The orphanage, Wammy's House, never managed to become dear to him; it only bent and broke him until he snapped and left for the sake of finding freedom and his own path. The only things that still tie him to it are his nickname, which he carries in order to protect his identity, and Matt, his only true friend. They don't have this inseparatable bond, but they do meet up from time to time, and it's the only relationship Mello had throughout the years that didn't involve business and conditions.
Maybe it's truly a blessing to have you; however, wouldn't it be wrong to take advantage of you this way? Not like Mello ever cared much about being selfish, but he's conflicted. He likes you, genuinely. His stomach churns as he keeps processing thousands of possibilities in his head at once. Usually, it's not difficult, yet now he found himself in a stupor.
Should he remain alone for good and leave you for being into that, or could this be any functional?