Rose: Rise won't fit inside a bath rub due to her height, so the closest thing you can get to a genuine bath time with her is swimming. It's usually both of you splashing each other in the water, and you laughing at Roses' straight pink hair.
Garnet: You both actually sit down inside and talk about anything. Sometimes it goes from space to ice cream, and you both spend so much time in there that you forget to get out.
Amethyst: Bubbles. Amethyst will hide underneath the bubbles and you both make wizard beards for each other. It's really rare you both have time to spend together like you do during bath times.
Pearl: She needed help understanding a bath for the first time. She wasn't shy at all, but really confused. Pearl actually found it boring that you sit in water together. But you distracted her by conversation, and you both clicked, talking about life and troubles.
Peridot: Bath times are always weird with you two. It usually begins with you dumping water on Peridot's fluffy hair and trying to flatten it down. Then it moves onto you helping Peridot shampoo and condition her hair. You both find it entertaining, and sometimes Peridot will agree to help you with your hair too.
Jasper: She thought the idea was lewd, and she didn't want to do it.
Opal: It's not even champagne in the bath, it varies at times. Usually it's juice in cups, or sometimes it'll be soda. Opal will find ways to make bath time fun, and will sometimes put bath crystals or bath bombs in there to make the water look like anime water or cotton candy colored.
Sugilite: Your baths are out of the ordinary. You both only bathe together when either one of you is upset, and you both drink alcohol to bring your bum mood down. Then you both splash each other to cheer each other up, and it always ends in the bathroom floor getting wet and slippery.
Sardonyx: She loves to drink wine in the bathtub. You've drank it once, and your face had shriveled due to it's bitter taste. A bath to you and Sardonyx is a small celebratory occasion, and you've accustomed to bringing root beer in for you and wine for Sardonyx.
Alexandrite: You both prefer showers. And even that's crazy. Your conversations are mainly politics and social justice issues, you and Alexandrite will discuss the matter while shampooing and conditioning each other's hair. On a rare occasion, one of you will have to help get soap out of the other's eye.
Malachite: Your baths are never PG13, and will always end up in a rather l00d ending.
Stevonnie: You two can never be serious. Stevonnie will put on a bubble beard and pretend to be a politician, or Gandalf....or Dumbledore.
It's always a contest between you and Stevonnie, whoever can make the best impression wins. It's always mostly Them who wins.
Rainbow Quartz: Baths can never be ordinary. Baths between you two are planned, and it definitely has to be romantic. There's candles (that you're very concerned of) and of course champagne. It is nice to take a break and unwind with your girlfriend, so you can never exactly hate the romantic setting.