The couple didn't have much time to be with each other for the last few weeks, and they would separate again. Michael felt bad about that, but it was not like he could bring Alice to the Nest. He'd already asked Eren if he could get someone, but the Curse User said only family members were accepted into the Nest.
Sometimes, even family members were rejected. It happened often enough. After all, Curses drastically affected the Fate of ordinary beings. It was best for their safety to avoid too many Curses, and Curse Users. The farther, the better.
Peter Fang, for example, had merely been lucky enough to be his father-in-law's disciple. He knew a lot about Curses and had been under enough influence of multiple Curses' – Evalynn Fang's and her father's – that it made no difference either way.