Petelgeuse Romanée-Conti/Relationships

Fortuna
Like Emilia, Petelgeuse cared deeply about Fortuna, visiting her often and even helping her village in Elior Forest by sending supplies. He treated her respectfully and was visibly embarrassed when Emilia compared them to parents, indicating that he possessed romantic feelings for her. He risked his life to save her and went completely insane when Pandora tricked him into murdering her. He lost all memories of her along with his past after the tragic incident.

Emilia
Petelgeuse knew Emilia when she was a child, often visiting her and her aunt Fortuna, enough to be described as being like a family. He cared about her deeply as he attempted to protect her with his life when Regulus and Pandora attacked her forest. Furthermore, Petelgeuse cried tears of joy when he met Emilia for the first time. He told her that she (Emilia) and others saved him. He had already known about her even before meeting her. However, after he went mad, he no longer recognized her.

Flugel
Petelgeuse was shown to be acquainted with the sage Flugel. It can be easily deduced that he respected the sage greatly and Flugel in turn trusted him, as he entrusted a box containing the Witch Factor of Sloth to him. Petelgeuse apologized to Flugel and asked for his forgiveness before he absorbed the Witch Factor.

Echidna
Petelgeuse evidently had some interaction with her, as he tutored her created Artificial Spirit and "daughter" Beatrice, with Echidna in turn entrusting him to teach her some manners. Their relationship was rather cordial, as Petelgeuse joked around her.

Beatrice
He was her manners teacher 400 years ago when Beatrice still lived with Echidna. However, Beatrice stated that she disliked him, considering she said similar words for every other person she ever interacted with. Even after he went insane, she felt some grief for him when he died, saying how even he left her behind, using his old nickname.

Witch Cult
In the past, Petelgeuse apparently helped create the Witch Cult and was the leader of the moderate, more friendly faction at the time (with Regulus leading the radical faction.) The members evidently held him in high regard and respected him, with them delivering supplies to the elves of Elior forest despite there being no need to, and one of his fingers, a higher subordinate, sacrificing himself, to help Emilia escape from the Kurohebi. Even after he went insane, they still carried out his orders without question and were diligent, despite him occasionally pummeling them for various reasons, most being described as "slothful".

Regulus Corneas
Despite being fellow Archbishops in the Witch Cult, the two showed outright dislike for each other, with Regulus slandering and mocking him. However, it is apparent that they did cooperate on occasions, albeit reluctantly, as Petelgeuse had previously made a pact with him to leave all affairs in Elior forest to him, as well as stating they could have discussed the matter at the Witch Cult's church. Regulus also possessed a slight envy of him for people regarding him as the leader of the Witch Cult due to him playing a part in the creation of the cult.

Pandora
Despite Pandora being a higher ranking of the Witch Cult, Petelgeuse, like most members of the cult, viewed her as a taboo and knew how dangerous she was. Pandora, in turn, viewed him with respect and appraise due to his resolve and determination to save his loved ones. Pandora was also the one to name him the Sin Archbishop of Sloth, a title which he initially rejected, although he accepted it with pride after his descent into madness. After going insane, not much interaction was shown between them, but it can be deduced that he was much more respectful toward her.

Sirius Romanée-Conti
Sirius is Petelgeuse's proclaimed wife. Although Sirius loved him deeply, there was no hint that Petelgeuse ever reciprocated her feelings, due to his blind and one-sided love towards Satella. Sirius mentioned that he allowed her to borrow his things, sleep next to him, and didn't tell her off when she expressed her love toward him, although it is highly likely these were all part of her delusions. After the events of Arc 3, Sirius traveled around the world, located every last surviving devoted member of Petelgeuse's group and tore them apart in search for her beloved.