Fumi has officially been with Shinobu for probably just a few days, and she knows that he once had deep feelings for Sakura. Perhaps she feels she hasn't been able to replace Sakura's memory yet and is becoming impatient. Sorry, I accidentally wrote in my native language.
No you're fine! It just confused me cause my comment was also in Vietnamese. No fault of yours, again my signal just doesn't allow quick download speeds.
To my knowledge I don't think it's official that they're dating. Save for the sex, we haven't seen them holding hands or anything.
What i'd like is for Sakura and Shinobu to meet. They catch up, maybe clear the air.. but she then tells him she's going back to Guavure work. With Mio being there Shinobu will support this choice since someone they know is to be looking after her.
At the same time this talk steels his resolve to keep Fumi safe? I think that'd be a good ending surprisingly since I'm just now thinking of it. Sakura will feel that assurance with Shinobu supporting her as a friend rather than a lover or manager like the old days.
Though it'd also show the love she had really was shallow.