I'm looking for a couple of Belial stories involving people merging with one another and taking on a single identity. Any recommendations would be nice, but there's two old stories I've been searching for:

-A couple merging together into one 'child', a combination of both their identities.
-Two women merge into a double-ended vagina woman, and though they keep their old identities at first, soon they think of themselves as just one creature.