Both were singers who criticized Ryan and friends, though they ended up in different places.

Maybe they met a few times? If anything to hang out and talk shit about Ryan? Even if they never collaborated on anything, I'm sure they'd have lots to bond over, between musical careers and how much the people running Rapture suck. Friendship or romance, making sweet music together figuratively or literally, just put them in the same room together to air their Rapture grievances please!