So, he helped this girl do exactly what his childhood friend did to him, breaking a big part of his heart? Pretend to emotionally NTR her crush to provoke 'jealousy'?
Is this supposed to be a joke? At least Suzurikawa didn't say to Yukito's face "yeah I got my cherry popped by senpai", and the manga spent 20+ chapters trying to redeem her. Why on earth would Yukito would be okay with this plan (even without the 'first time' remark) when he himself suffered from the exact same and was all suicidal about it later?
Also,
@asphyxiav2 this isn't related to this chapter, but why are you translating it as "kaa-san" instead of "mother"? It sounds pretentious when "mother" works perfectly fine, or its many english variations with their own subtle meanings like 'mom, mommy, mama, mother, ma, etc'