I dont know if this is relevant since it's not actually Free!related but Eri Kitamura will be releasing a song at the end of October with the title "Rinrei/凛麗". While it's not exactly RinRei/怜凛... it's still Rinrei, right?
Rei: Nagisa-kun, can you translate “Kiss me” into Japanese? Nagisa: Isn’t it just “kiss me”? Rei: That’s what I thought. I overheard Makoto-senpai saying “Kiss me” just now. Nagisa: Huh?!? Who did Mako-chan say “Kiss me” to? Rin: Both of you. Your pronounciation is horrible. It’s “Kiss me.” Rei: Rin-san! Nagisa: Next episode, “The Locomotion of a Twist!” Rei: Kiss me. Rin: Kiss me. Rin: Perfect body. Rei: Perfect body.