okay...what was really Sae's plan here? A BJ for what? she never gave him a reason. she's lucky ohtori did what he did and bought her something she liked but she never made a deal with him so shes relying on this possibility ohtori would buy her things cause what? hes fat and a virgin? the hell is that.
just being surrounded by people with bad intentions and parental neglect I guess it makes sense the way that he is currently.