The last thing Dabi wants to do in that moment is wonder how his baby brother learned to suck dick. He already knows he'd have that ugly jealousy coiling in the pit of his stomach and it would sour a lot of things. He'd be a hypocrite, you don't live on the streets like he did without doing things that most would think of as unsavory. Or that taught someone much too young how to suck a guy off without gagging.

So instead he just takes the direction and lets his fingers curl and tug at short white strands. Hips snapping up to push his cock down the others throat before backing off and letting him go at his own pace. It felt good but for now his goal wasn't to just use Natsuo, his brother was too precious for that.

"That's it Natsu, so good." He murmurs, almost surprised when there isn't smoke rising from the seems around his face. "So eager for big bro's cock, yeah?"