Sirry Usly:
meanwhile in Xiang's married life, XY is still trying to poison him ?
Of course!
Making poisons for XL became a sign of affection between them a long time ago. When she delivers them, it shows he's in her thoughts. When she initially makes them taste bad on purpose, it shows that she's not afraid of him. It's one of the first ways that she starts to push boundaries and play with him. Later, when she puts lots of time and care into them, it also a way of indirectly showing that she cares about XL. And when she tells him that she can't make poisons for him after she gets married, it's another way of signalling the status of their relationship.
Edit: Whoops, your emoji showed as a question mark so I thought this was expressing confusion ^^" My bad!