I had the same questions about relative alcohol levels as some of the other commenters so I reviewed the past couple chapters. Wei Yuxi was shown as very drunk in chapter 5, when Fengtang protected her from those guys. But then at the end of chapter 5/chapter 6 its a few hours later and while Wei Yuxi is likely still drunk, she has sobered enough to be able to walk/talk/think. In contrast Fengtang seems like she was incapacitated to the point of not being able to string sentences together. So I'm not really buying a "they were both drunk" excuse; Wei Yuxi was sober enough to know better.
This makes Wei Yuxi a giant hypocrite: She liked Fengtang because Fengtang stopped her coworkers from taking advantage of Wei Yuxi's drunkenness. Then she turns around and takes advantage of Fengtang's drunkenness? What the fuck? I really hope Fengtang calls her out on this next chapter, and that we don't just gloss over how terrible her behavior was.