Anyways some rambles about them and their dynamics under the read more
Note; each poly ship technically exists in its own canon. Though it'd be really funny to consider the massive puretail poly, maybe I'll do that later lmao.
Shmilk is exclusively dating Cattail but is. friends(?) with Pure Vanilla. He still torments PV, though it's not as malicious as it used to be. If he goes too far PV is fully capable of putting him in his place (partially due to Cattail's influence of "aren't you tired of being nice, don't you wanna go apeshit").
His relationship with Cattail is playful and, if we're being honest, a little terrifying to outside observers. They routinely hunt each other for sport and often get roughed up because of it, and their playfights can be mistaken for genuine murder attempts. PV is the one who ends up healing the two the most, though he does get fed up with the two of them frequently (nothing that some TLC from his wife can't fix).
PV typically stays out of their dates, primarily due to the dangerous nature of their games. Shadow Milk on the other hand regularly drops in on pv and cattail's dates just to be a bother.
White Lily's relationship with them is a mutual crush that has gone nowhere. White Lily is deeply afraid of pursuing a romantic relationship with anybody, let alone cookies she feels she betrayed deeply. She feels that she must come to terms with the sins she's committed as Dark Enchantress cookie before she can accept being loved, and she's afraid of settling down somewhere.
Cattail and PV are both understanding of this and allow her to come and go as she pleases, and never pressure her into doing more than she's comfortable with. She has 100% kissed both of them at some point though.
Their relationship with Angel Chiffon is primarily romantic, with Cattail being Angel's primary partner.
Angel had a crush on Cattail for around 1000 years or so before PV showed up, and had accepted that his crush would go unrequited for pretty much forever. PV was the one who brought up the idea of dating Angel Chiffon to Cattail, and Cattail readily agreed to bring her into the relationship. Angel Chiffon's relationship with Cattail didn't change much after they started dating, only adding kissing and making out to the already pretty regular physical touch.
Angel Chiffon and PV's relationship moved a little slower due to the mild jealousy the two would experience, though they got through it fairly quickly through communication. The two bond over being healers and often remind each other to stay healthy and that their own healing is important.
PV and Cattail do plan on marrying Angel Chiffon eventually.
Black Sapphire's crush on the two actually started while on a recon mission in the Vanilla Kingdom, where he meets Bulrush and Vanilla Orchid (cattail and pv's civilian disguises). He gets a crush on them after interacting with the two and only realizes later that it was Cattail and PV, and he does eventually get dragged into their relationship at Pure Vanilla's suggestion.
His relationship with the two is playful and lighthearted despite being enemies in the past, though he often ends up flustered and embarrassed. As suave as Blapphire can be he is utterly helpless to his partners, whether they work together or alone to fluster him.
Group dates are extremely common, though they do on occasion have singular dates.
