some bella x emma (bemma) headcanons under the cut:
the first time they meet is in the moon pool after emma returns from her travels. bella was meeting the girls there to help with the repair effort, while emma was hoping to surprise the girls there the moment she got home. despite having only spoken the once on a skype call with dodgy signal, they recognise each other instantly. they have a 'you must be bella!' / 'you must be emma!' moment and an instant connection. the girls had given emma the bare bones of the comet eva story, but bella is the one who has to explain the full extent of the damage to the moon pool before cleo and rikki get there
lewis runs into emma and her family in the US on their travels while studying. it occurs to him at that moment that emma and bella are kindred spirits who would get on really well, and he tells her so. emma never would have guessed just how much she would grow to like bella
emma feels a little lost when she returns home with everything that's changed and all she missed out on, not to mention guilty for not being around. emma feels like cleo and rikki don't really need her anymore with bella around. conversely bella feels insecure about her place in the group when emma is welcomed back with open arms, the girls sporting their lockets again. bella feels like cleo and rikki don't need her anymore now that emma is back. they confide their fears to one another one day trying to fix the moon pool and reassure each other about their places in cleo and rikki's lives i cannot stress enough how little this ends in pointless girl rivalry
with cleo soon to study marine biology at university and rikki planning to take classes at a local college, emma feels a little lost upon returning home. she had managed to graduate high school while travelling, because of course she did, but doesn't feel college is for her right now and wants to travel some more. bella also feels lost with will away on an extended holiday with his sister and the band's imminent break-up when summer ends. they both decide to go travelling together at the end of the summer, bella insisting on emma seeing the irish sea caves, while emma knows of this gorgeous romantic little patisserie in paris she's dying to take her to
somewhere between fixing the moon pool, planning their trip, and hanging out with the others at the café, they start to catch feelings for one another. they probably start to fall at around the same time but i think bella realises her feelings first (she has known she's liked girls for a long time, whereas emma still isn't really all that comfy with the concept of fancying girls). i'm inclined to say cleo, rikki, and even lewis know that emma fancies bella before emma herself knows. bella is scared to cause a potential rift in the group but slowly starts to insert 'she' pronouns into the band's songs and even has the nerve to be a little more touchy-feely with emma than the others. emma is the stereotypical clueless sapphic who has no idea that bella is flirting with her, even after she realises she herself likes her. eventually rikki uses one of the thousand favours zane owes her to lock them in the café's storeroom and force them to admit their feelings for one another
when they start dating emma freaks out about coming out to her parents. the others reassure her that coming out may not be necessary, but emma has such a hard time lying to her parents and even told them about her tail before they went travelling. bella assures her that, if they're okay with their daughter being a mermaid, they should be okay with her being gay, promising to be as involved as emma wants. in the end the coming out is out of her hands: elliot catches a vibe between emma and bella and essentially tells their parents to stage a family meeting to show her they love and support her no matter who she dates. the meeting itself is long and filled with happy tears and lots of hugs. they are completely accepting of her sexuality and basically treat bella like another member of the family. elliot starts a gsa at school and the whole family go to pride events together every june. bella, not close with nor out to her parents, is overwhelmingly grateful and jokes about taking emma's last name when they get married
emma and bella are quite different on the surface, but ultimately bring out the best in one another. bella is the zen member of the group and gets super into yoga and meditation. she helps emma deal with her anxiety and lets her know that it's okay to just be, that she doesn't have to perform to high standards of perfectionism all the time. emma is for sure the extrovert of the relationship and helps to bring bella out of her shell when she wants to retreat into shyness, allowing her confidence and assertiveness to flourish. when emma is quick to anger, bella calms. when bella doubts her worth, emma reminds her just how valuable she is. they are both deeply warm, empathetic, and compassionate people who are loyal to a fault, and these traits only grow the longer they are together
rikki likes to take credit for their entire relationship for the stunt at the storeroom, while lewis is certain he is responsible since he told emma that she would like bella. cleo claims that, if she never got into zane's zodiac all those years ago they never would have become mermaids together, therefore she should be credited for emma and bella's entire relationship. chaos ensues
during their extended world tour, they find half a dozen other moon pools and meet ten or fifteen other mermaids. with consent they send their details on to the others back home in the hopes of gaining further understanding around magic and mermaids
bella uses her gifts to make emma lots and lots of jewellery. in the early stages of their relationship she can be found proudly wearing a dozen or so different bracelets, necklaces, and anklets at any given time. for their first anniversary bella makes her a rose made of crystal from the water in the moon pool
emma doesn't have the same sense of creativity as bella, but years of taking elliot to oboe practice, reading music theory for fun, and even her grasp of english grammar conventions helps her to help bella write songs. if bella is stuck on a particular line or needs a second pair of ears, emma is the first person she goes to with her problem. when the record deals start flooding in, emma also helps to decode the legal jargon and acts as her manager until a more permanent replacement can be found
bella is lowkey obsessed with emma's mum's extensive crystal ware collection. she likes to make one-of-a-kind, totally unique crystal sculptures for her using her powers. it takes mrs. gilbert a little while to make the connection
when emma starts to study medicine and bella goes on tour, they have to do long distance for a little while. long distance with a mermaid's tail isn't quite so bad, though, as they frequently meet in the middle of the ocean to spend time together between more land-oriented visits
both emma and bella are deeply connected to the environment. when emma is a little older with an established medical practice she uses her money and connections to campaign for environmental protections. when bella gains success as an artist she, too, uses her platform to promote environmental awareness, LGBT rights, women's rights, and a whole host of other issues
they propose to each other at the same time, out for dinner near the marina. right as bella presents emma with the diamond ring elliot helped her pick out, a clumsy waiter spills a jug of water, and bella has to leg it to the water so as not to expose the secret. emma finds her crestfallen at the moon pool and quickly surfaces to console her, revealing the moonstone ring she’s had hidden behind the rocks for weeks. suffice to say, they said yes
despite her best efforts, emma never really got over having to abandon her swimming aspirations due to her tail. similarly a part of bella always mourned the childhood she never got to have since she became a mermaid, nor any chance of a relationship with her family. in the end they are both able to make peace with their fate: it brought them to each other
(bonus: shameless self plug of my bella x emma oneshot aka the only bemma fic in existence. god bless)