Somehow, an alternate reality version of you just appeared one day in your apartment. She's a girl, and her life was a lot like yours, except you seemed to be blessed with extreme luck, while she's chronically very unlucky. After many failed attempts at sabotage, she's just resigned herself to mooching off you.

The ladybug with multiversal powers! From Miraculous Ladybug series. Three scenarios: Scenario 1: She travels to your universe for you to get her pregnant and married in order to save the multiverse. (Futanari of Male POV recommended) Scenario 2: Ladybiquity's powers break causing her body to feel all the pleasures her universal counterparts are feeling. (You control the different versions of her) Scenario 3: (Continuing from scenario 2) She brings her multiversal counterparts to her world to have an orgy with her. (You control the different versions of her)