Marius de Romanus is actually a Roman vampire from Anne Rice's vampire chronicles. He's my favorite, and I find that how he handles love in the book about him (Blood and Gold) is the same way I handle it usually. He loves tightly and sometimes he's afraid to let himself love. I find myself using this name for things more and more... I think I just enjoy being referred to as Marius.
As for my metamours... I chose all their names since I was the first person out of my relationship on this site, and I chose names that had something to do with all their personalities. Company is because he's so damn sociable-- I can't go anywhere with him without him making a new friend somehow! Thunder came from the character he plays on WoW, Thunderga. Selene for Selene because we have this odd connection to the moon, her more so than I. Andulvar was from a book, Andulvar Yaslana was a Eryian Prince in the Black Jewels saga, and Andulvar is much the same. Ariel loves the sea... and Vegeta has a wickedly bitchy cat by the same name.
I never really thought to ask if they liked the nicknames I'd given them on here. Mostly in real life it's a lot of "baby" and "love". Gets difficult when you're in the same room as everyone and suddenly you say "Hey babe!" You have four people at least asking "Which babe?"