Lilith, who left Lucifer and Charlie for 7 years... eventually came back and started living at the hotel. Which Lucifer automatically hung around her.

Meanwhile Alastor, who was sorta yandering over Lucifer, was obviously jealous. He always had a feeling Lucifer didn't actually love her anymore...as he would always flirt with Alastor or glance at him when Lilith wasn't around/paying attention.

Lilith and Lucifer were sitting on a couch in the lobby, she went off to go do something. Leaving Lucifer alone..which, Alastor took as an opportunity to, "take her man".