I haven't seen this on MangaDex, but it looks like an illustration for one of the newest chapters. Koi's arts are becoming more and and more crazy beautiful with each volume ❤️

I've been hasitating myself for so long posting these cover arts on Danbooru, because they are "hard-translated scans", but since Mangatimekirara's twitter posts them digitally, so I finally gonna do it! (though scans quality looks better than twitter images... )

Scan:

Same art but on Twitter