ThirtyTyrants
Gu Wei's gift was probably both the wine and salve/lubricant in the jar. Should both decide to consummate their marriage, Chu Yun wouldn't be in too much pain before and the day after... I'm curious to know what the Rites person said for Chu Yun to display his animal form and would Xiao Zai comply. Can't wait to read more.
Best guess to the contents of the pot is lube, lol, though not sure if that would really help if Xiao Zai is less than a gentleman... so maybe something more interesting. The fact that he expressed even mild concern that his own precious son might be less than the gentleman he raised him to be, intimates his own experiences and mistreatment. I don't think Chu Yun had picked up on that yet because he can't imagine an Omega being abused.