My Husband and I Sleep in a Coffin novel volume 1 was written by Wu Shui Bu Du.

Wang Xiaomie, a reclusive gay virgin, wakes up to a shocking reality: he now inhabits the body of a thousand-year-old corpse, dressed in elaborate wedding attire. Even more bizarre, he finds himself sharing a coffin with Wen Fengjin, an immortal warrior who has spent centuries waiting for the return of his lost lover!

Now trapped in a lavish mausoleum, undead and constantly ravenous, Wang Xiaomie's only source of sustenance is a magical peach blossom tree that keeps his heart beating. But survival isn't the only challenge—he must also avoid grave robbers and, more troubling still, conceal his growing attraction to the hot, yet utterly unhinged, immortal who will stop at nothing—even murder—to protect his beloved.