
Wasn't the safe word macarons?

it's not uncommon to have two safewords. either in case you forget one, or for the red/yellow/green system.
Red = stop everything.
Yellow = stop this particular thing or slow down.
Green = I like this/keep going.
One is a more firm stop than the other. so maybe macarons were the yellow safeword and vanilla the red one. or they have two so they wont forget. Just a guess on my part thought ^^

Can anyone tell me the name of the manga on the credit pages

Ohhh I get ya! If I’m not wrong, is this one:
http://www.mangago.zone/read-manga/19_sai_no_porno_endeavor/

I see yall in pure vanilla land a lil slap to the face in a S&M relationship is SOFT

Agreed. That was the kind of s&m relationship thy had. MD gave him an out multiple times. It was chanwoo’s decision to continue. Yes, chanwoo feels betrayed right now, but everyone seems to forget that chanwoo literally just tried to introduce MD to his new boyfriend after he rejected MD. So they were both slapped in the face.

The slap probably wouldn’t be psychologically hurtful in a different scenario. I agree with you that what MD is doing now isn’t right. Chanwoo is vulnerable with his emotions right now, so he may take the usual s&m acts differently. He is pushing himself past his limits at the moment, which isn’t healthy or safe. Frankly, I am disappointed with both of them. MD is being a little cruel, and chanwoo was being thoughtless and inconsiderate.
Translator-san said what they said and I don't wanna see any of you musty bitches complaining