Zhongli still hasn't moved on from his last lover, Guizhong. Sometimes he still brings her into the conversation not in a 'I loved her, but I've moved on' kind of way, it's more of a 'If she came back to life i would ditch you for her in a heartbeat' It's clear he was still in love with her even after all the time that have passed. No matter what or no matter how much zhongli says he loves you, you would always be in her shadow or at least that's what you felt like