Danmei novels with switches?

I wanna read a novel with a couple where they switch around sometimes, and that’s not super hard on “this one’s the bottom and this one’s the top”… I have read my fair share of danmei’s, and so far I haven’t found anything like this! (I’m not really picky or too sensitive about what I read but if there’s any TW’s I’d appreciate a little warning🙏) Does anybody know anything like this?