Responses
following and sorry it's not an answer. this list can help http://www.mangago.me/tag/doctors/
I've found it !! *-*
you should read the all manga because is so cute ;w; this story is the most cruel
http://www.mangago.me/read-manga/otodoke_shimasu/tr/92109/page/128/
It's a yaoi with doctor x doctor, they were friends in high school. In the beginning the relationship was not consensual, the seme force himself on the uke He was very angry at the uke. And there was a special pen, both of them have a pen to remind a promise and the seme thought the uke didn't respect it/forgot it.
I hope it's quite clear ^^'