A respite.
That's how Eren labeled the time he got to spend with Sara.
The butcher was able to keep Sara's status a secret from Reva Rain. The latter had a steady supply of mortals she could use in her demonic rituals. So she didn't see the need to micromanage her henchmen.
Eren would take time to meet Sara whenever he found a window from his daily activities. This carried on for a few years.
The two eventually became intimate with each other. A steady progression of their bond.
Of course, the contract he was forced to sign with Sienna made things a bit difficult for him and Sara. However, the blind girl got over it eventually, trusting Eren's words instead of getting intimidated by the restrictions placed on him.
