So I'm doing rewatch number whatever, and just finished To the Stars. As usual I'm reminded that it's heavily implied Rick and Minmei finally smash in the previous episode, and literally the morning after Rick is full on doubting the relationship, while Minmei is paranoid and overcompensating.
Which always prompts me to laugh as I contemplate this point:
The sex must have been truly, epically, unsatisfyingly terrible for one or both of them.
Because for Rick it's like the fever finally broke, and it's so definitive that after Lisa's confession he leaves Minmei to her own devices in the middle of a combat zone, without so much as a "Get to a shelter."
To be fair to Minmei it may not have even been anything she did wrong as far as sexual talent. The wholesome read on that is they finally did it, and that's what it took to start realizing they didn't have a real romantic emotional connection. It was just their shared baseline hotness, trauma, and conditioning from all the rescues over the years that made them think so. She goes paranoid as she has put all her eggs in Rick's basket, while Rick starts to nope out as he does have an actual romantic option in Lisa and a life with a strong sense of purpose that he shares with Lisa to boot.
But like I said, I'm always amused by the "Finally hit it. Instantly wants to quit it." aspect of the episode.