I'd be a bit curious about the reasons why his other live-ins did not work out, especially in those cases where the relationships are ongoing. It might be useful to speak with her and find out why she chose to move out (if it was her choice.) Oh, there are plenty of good reasons why people can't live together. But personally, I would just want to make sure I knew what they were, to make sure they're good reasons. If "she was too jealous so I asked her to leave" is on the list, I would stop packing my boxes.
“As I am sure any cat owner will be able to tell you,
someone else putting you in a box is entirely different
from getting into a box yourself.” —bisexualbaker