Same, this is what i said yesterday to somebody on another comment:
I'm starting to think that 704 and GM were together, before everyone around GM lost their memories. Especially after reading this chapter it seems like it was kinda hinted. I tried to translate the latest chapters in the raws with google translate and when GM is talking to San he is saying that he is marking 704 so that nobody else would be touching him since goblins don't like "used goods" but it seems like San isn't buying GM's "evil guy act". GM also offers to tell San about his history and that once he does, San won't be able to go back.. San declines in the end and needs some time to think about it more.
Now that's some hot tea
Guys I think I've figured something out!
I think there might've been something going on between G and 704 when he was a human, hence why he was talking abt "what was his" they might've been dating, tbh that would explain why he's so attached to him. I'm kinda shook