I don't know if i should thank Truck-Kun for this gift or, hate him for what he did to this innocent gal.

The main issue with necrophilia is that an ordinary corpse is incapable of giving consent. Having sex with a zombie is still pretty gross physically, but a zombie able to give clear, willing consent (I. E. one able to talk, of legal age*, retaining all or most brain functions, and not under control of a master) isn't really different from a living person morally.

*Time spent dead does not count. The jury is still out on whether or not time spent undead counts or not.