No he never cheated.... the only sexual thing is ch 4 and 12
In ch 4 doctor went to red haired sex friend to use him as surrogate for uke because he was aroused by uke/his patient.
In ch 12 it was an out-of-nowhere threesome and doctor and a guy were with the red haired guy.
When doctor starts dating uke, he will abandon his sex friend
I didn't like doctor in ch 12 because he went to red haired sex friend again ..i mean in ch4 it was because he was turned on by imagining uke so he went there and used red haired as surrogate....but in ch 12 he went to him again....well i guess he didn't have a choice because uke was just a patient whom he had a crush on but sadly uke had a girlfriend and seemed straight. So gradually doctor's crush grew until in chapter 15 or 16 he took the chance and confessed
Okay....can someone just tell me of he cheats on him? Spoilers! I have to prepare myself ╥﹏╥