HELP ME FIND THIS YAOI MANGA!!!!

So it was a doctor themed and all I remember is that in a chapter that seme said they should breakup or something and then later on the seme's ex girlfriend or something attempted to stab the seme because he didn't want to get married or something but instead in knife stabbed the uke who tried to protect him.
Can't remember the rest but please help me find it!

（亅^~^