Every relationship is different. The only fact that counters this observation is that every relationship is the same. Are we all so boring? The stats speak for themselves.
There are a squillion billion people on the planet (approximately) so you can’t generally generalise. You can’t say, for example: “Everyone who lives” – point a finger – “there, has no sense of humour.” Or, “Everyone who lives over there” – wave an arm towards another part of the globe “is too frivolous”.
You cannot say everyone is different ‘cos they’re just not. They are the same. They do the same things. Think of the weirdest, crankiest thing someone might do (collect tummy-button fluff) and sixty million other people (these figures have not yet been verified) do the same sort of thing; they collect airline barf bags, or they’re into competitive dog grooming, or yodelling.
Bottle all that weirdness into your romantic novel and you’ll make an engaging plot and a fascinating story.
Sadly, however, most ordinary people do things that nobody wants to read about.
Even TV series about ordinary lives aren’t about ordinary lives: everyone steals everyone else’s partners, every house gets burgled, entire streets get sucked up into alien space craft. On TV, nobody just goes to the store, comes back, cooks and goes to bed … unless there’s a rare tropical and poisonous thing already waiting in their bed.
So, in your efforts to make your main characters different but the same, avoid these five danger zones and you should be OK...
Dead puppies: Killing off cute little animals to bring people together is just schmaltz. Buy a puppy together but don’t grieve over one.
PTSD: Screwed-upness due to a minor upset might get a sympathy kiss from the heroine (and move the story closer to luurve) but unless the guy has just returned, scarred and emotionally frazzled from a major war, don’t go there.
Violeence: You have two choices: Go for your Pulitzer, or don’t. If you choose ‘don’t’ then nobody needs get hurt. If you go for ‘do’, then you’ve pretty much got to smash 25% of your cast around a little.
Terminal illness: Really? The cancer/AIDS/ebola thing is so out-dated. The lingering last words and final kisses? Let ‘em live. Life’s too short without us finishing them off.
Terminal dullness: Life does tend to skewer towards the dull end of the interest spectrum so you have to spice up your relationships a little. It’s not enough that the guy does an interesting job and the girl is a celeb incognito.
Consider instead: a slightly sick pet, a hero who’s fought the Abyssinian war single-handedly, a heroine with hay fever and brittle nails, coupled with a marginally lingering emotional upset from a very small disagreement witnessed first-hand on a sunny Caribbean island.