I always thought of becoming a Worm that walks being the sort of transformation a woman would take, because as women, they might still have some degree of vanity left in them, and the transformation still let's them retain their own figures, even if a bit more grotesque.
This Gross factor goes down significantly when you consider the prospect benefits of fucking a Worm that walks if it's not just worms, but instead, that + body oil, so it makes less of that nastly writing sounds and more sounds like they're basically an infinite pleasure morphic fleshlight that is fairly warm because of the friction and transferrance of heat in the memorized hive-mind form it inhibits.
In addition to it's almost amorphrous state, that means the replicant orifices are going to be pleasure zones of constant attention of 100% semen draininng efficiency, never mind body movements which can border on the bizzare "Missing a few bones sort of movement" to every inch of this body moves like a sexualized perfectly weighted jiggle sway child-birthign hips ratio of "I'ma fuck that insecxtual collective".
I always figured in the case of a Lich and worms that walk that they'd be found in Duo's as Actual Spellcaster couples because one preserves vestigal remnants of their beauty, and the other preserves it's power, masculinity, and X everything that some devoted woman would see in her man-post Lichdom in that fanatic "You've made me wet/moist because of your badass conquering of death" sort of way.
One idea was for the Lich to give himself that actual one rae diesease that literally causes a skeleton to take over it's owners body by replacing/growing over existing muscle structure (yes this is real) then become a Lich so it becomes this defined ultraskeleton of the Male form, grafting a Morag parasite to himself for a pseu-tongue/Appendage.
The wife, Worm that walks, would use modified carnivourous worms, (Illithid Larvae as a workaround) and would become a Psionic mass of juvenile Vulpotus collective Mind flayer worms as a worm that walks, and would be capable of suggestively, sexually, and symbiotically fusing with her partner to act as Pseudo-psionic muscles for her Muscle-Lich Husband.
It'd be the most cute amd unholy union ever, and the sex would be abominable, like, to replicate it, you'd need melons, fleshlights, cornstarch fleshlights, rubber glove and sponge fleshlights, spaghetti, jars of mayo, and the noise your balls make after a shower when they hit against your legs, combined with phomatic sonic voice effects of psychically projecting undead creatures moaning in morphic jiggly bizzare positions and other stuff, generating shitloads of negative energy from the contact.
Both get Lichloved status, and you can sure as shit tell when they've done it, because the Liche's flesh has "leftovers" hanging around on it from his Super Semen Demon/s's? contotionist bonless ultrasex.