Trashy parents in Japan are all about names like that.
https://japanese-names.info/column/an-introduction-to-kira-kira-names-beyond-the-old-fashioned-pronunciation-of-kanji/
Ah yeah it's most likely what @skyscar said, "if we get old and single why not move in together?".
Also from the context of Miharu then essentially saying "thanks" and the friend later going "well but before all of that -- why not talk to the guy?".
probably just a turn of phrase that sounds more natural in Japanese and is translated like that
Japanese people discover mental health is a thing other people can help you with for the 63rd time.