I can’t explain all those relationships! Even the characters involved couldn’t explain them. They’re a big ol pile of dysfunctional hipster vampires and their ships are a hot mess. 

BUT I SHALL TRY. Nobody attack this please, I’m grossly over-simplifying for the sake of this one Anon’s overwhelmtion ;] #your headcanon may vary, #ship and let ship.

At their most basic:

• Lestat/Louis – Murder husbands, OTP, 5ever
• Lestat & Marius – not a pairing, but there’s definitely a mutual respect and caring in a paternal sorta way.
• Lestat & Armand – not a pairing, but there’s definitely a mutual respect and caring in a fraternal sorta way MURDER BROS.
• Lestat & Daniel – they’ve not had a lot of canon interaction but I’d bet Lestat is forever grateful that Daniel basically started the VC which eventually brought him back together with Louis. There’s fic and RP (see daniel-james-molloy)​ out there that would support a Lestat/Daniel BROTP, possibly an actual ship, I likes it.
• Lestat/David – Post-TOBT David has had little canon interaction with Lestat in a loving fledgling/maker way. There have been one or two scenes of extreme feistiness between them, which were hot and problematic, but they seem to have reached a kind of amnesty and even care for eachother.
• Armand & Marius – have a kind of amnesty between them. Marius has done some pretty insane things for Armand, with good intentions, but still.
• Daniel is with Marius these days.
• David is sort of a loner but he does visit with Louis, Lestat, and Jesse on occasion. They seem to be his closest friends.

I would say that the relationships change throughout the series, and that some ppl simply do not include certain books in their headcanon, which changes relationship dynamics, too. Including “present day” ship dynamics. For example, if you don’t include Prince Lestat in your VC headcanon, then Marius and Daniel have a different sort of (probably specifically and clearly) platonic relationship than they do if you DO include Prince Lestat.

For more specifics, check out VC Wiki, but there’s gonna be spoilers. Fair warning.