i love the idea that the first time it comes around once they're together zhongli has this like... dawning horror once he realizes what season it is. he spends like a full week trying to just avoid childe (claims that he's just ill, hence why he's also taken the week off of work.) but they keep running into each other. at first it's because childe keeps trying to drop off homemade food for zhongli to eat while he's not feeling well :( or bringing him medicine. then it's bc childe is getting awfully suspicious with how flighty zhongli is being even just during little cutesy visits from his own partner.

their relationship starts slow bc zhongli is aware that childe struggles with intimacy a lot so it really is a bit of a problem when zhongli is insanely horny and fighting for his life to hold back... only to be a major relief when they do fuck nasty and childe admits how much he liked it rough and ~weird~ (though he's still rightfully a bit peeved when zhongli finally admits that he was just avoiding childe bc of his rut instead of explaining anything properly to begin with)