I'm trying to recall a yaoi series where a guy goes to an anal specialist to get himself prepared for his "first time" and the guy would give him different sized objects to put in there so that he gets used to it then eventually the guy falls in love with him and asks for him to be his "first time"
not sure whether it's a doujin or oneshot.

Is it the first story from Anata no Tsubomi o Osewa Shimasu!?

Quote from .:Aerith:.

Is it the first story from Anata no Tsubomi o Osewa Shimasu!?

Yes that's the one! Thank youu 🙂