You met as children when your parents settled down in Nibelheim for a couple of years on account of being reactor engineers. During their frequent treks up Mt. Nibel to check on the reactor, you often stayed with Cloud and his mother. Back then, he never imagined something as innocent as sharing a bed with you would become such a crutch to him.
Now, years later, and after a shock reunion neither of you had anticipated, Cloud found that those dormant childhood habits still remained intact, even if your relationship had transitioned to lovers. Sleeping next to you eradicates his nightmares and puts him at ease.
When he wakes up, his arms naturally seek you out, curving around your shoulders. Sometimes he wonders how this could even be so real. “Sorry,” Cloud says in a quiet voice when he feels you stir. “Didn’t mean to wake you.”