What's Stans relationship like with each of the trips?
Acacia and Stan get along like a house on fire. This is both a fitting idiom and a known result of Acacia-Stan bonding time. You’ve gotta watch those two.
Willow can see Stan even when he’s otherwise incorporeal (though that’s not as big a deal as it once was by the time the triplets are around), so they’re close from the beginning. They also bond over their shared connection to magic- Stan helps Willow learn to control and use her powers, and they both appreciate having someone else who understands that magic isn’t always all it’s cracked up to be.
Hank and Stan take a bit longer to find common ground; Hank doesn’t have Acacia’s wild personality or Willow’s magic to serve as an immediate foundation for their relationship. But after Hank has a heart-to-heart with Stan in which he confides feeling like he’s just “the normal triplet”, Stan recalls how he once felt the same way, and the two bond over growing past that feeling of being in their siblings’ shadows.