I know, right? Yet 'lover' is durable, timeless, no perfect substitute exists. Sometimes it is the perfect word … ex, main squeeze, significant other, boo — none of these really measure up.
Here’s a thought — a word I never use: bae. But I just googled it, and apparently some take it to mean “before anyone else.” Now that has a nice ring to it. What do you think — might be just what you were looking for.