Spoiler!!
In chapter 20+ uke experiences heat and the seme brought uke to his apartment and had ehem.. Smeggs and after awhile while they we're doing, out of foolishness, seme took off his condom and fucked uke again and came inside uke.. So in the morning uke forgets what happened that night and the seme gave him some sort of medicine which is a contraceptive pill.
My point is, seme is such a jerk, he already knew the consequences if he came inside uke and still did it.
Re reading this for the 5th time and it still amazing as ever