First of all -- thank you! So glad you're enjoying reading. Second -- such great questions! So much to think about.
Ok, so I imagine the relationship not following a typical linear path. In a lot of ways, I sort of envision my Neighbor!Frank stories to be a prelude to Boyfriend!Frank though there are a lot of differences between the two. They're not technically the same "character" but I still envision the relationship starting in a similar way. Meaning, you're in each other's orbits for a long time -- neighbors who rely on each other a lot (more like you relying on him more tho) and in a lot of ways, it's a very intimate, nearly romantic relationship. Frank sort of makes it his job to make sure you're taken care of, even if it is from down the hall. Hauling your packages up to your unit, fixing your jammed window, installing your garbage disposal for you.
And most of the time, he's anticipating your needs before you get a chance to ask him. Like that jammed window-- you worked up the nerve to knock on his door and ask for help and all you say is "Frank, I was wondering if maybe you could--" and he's finishing your sentence with "fix that jammed window? Yeah sweetheart, I saw your curtains blowin' in the breeze last night and knew that window must have been jammed open. Piece-of-shit landlord shouldn't be leaving you in a unit without locked windows" while he's grabbing for his toolbox.
And this goes on for months -- with the moments growing more intimate but still never romantic. Like when he was gone for 9 days straight and you couldn't stop checking the peephole everytime you heard footsteps. On the ninth day, when he finally came home, you barreled out of your apartment door and nearly crashed into his arms mumbling, "was so worried about you Frank. You didn't tell me you were leaving," and he's just rubbing your back and murmuring, "hey hey, I'm here sweetheart. Shit, didn't mean to worry ya -- just had some business I had to do. Hey I'm alright, I'm alright." And it was that moment that Frank decided he wasn't gonna leave you like that again.
Because as far as Frank was concerned, he was gonna stay in your life whether it was romantic or not. You were it for him. He was in it for the long haul. Now he was just gonna give you time for you to realize it too. And that came a few weeks later when a particularly pushy date was at your doorstep, pulling out every excuse in the books to get into your apartment, in the hopes of getting into your pants. He's got one foot in your door, going on and on about how he could really use a coffee and maybe you just could just make him a cup and you're politely declining over and over until you see Frank's door creak open and he casually leans against the frame, arms folded across his broad chest, and asks "everything alright sweetheart?" and the guy just cranes his neck back to say "fuck off buddy." Frank only smirks a bit before he makes eye contact with you and says "Say the word honey," and you just give him a quick nod. Frank is on the guy in two strides, stomping his foot with a sickening crunch and the guy is hunched and howling. Frank leans towards his ear, his arm looped around the guy's bicep as he hauls him upright and says "Apologize-- now" and the guy is spewing I'm sorrys at you as Frank shoves him with a "now get the fuck out of here."
Not a moment later and Frank is back in front of you, a hand cupped to your jaw and a thumb rubbing the skin of your cheek asking if you're ok and "he didn't touch you did he?" You lean into his hand and shake your head no, offering a quiet thank you for his help. You both stay like that a moment, reveling in the closeness. The safety of it. Frank's eyes are searching your face as he asks, "When are you gonna stop wasting your time with these assholes?" He had seen the dates come and go, never lasting more than a few awkward encounters. For a moment, you can't meet his eye but you force a smile and and ask "What asshole should I be wasting my time with?" He lets out a soft chuckle and his other hand lands on the opposite cheek, tilting your face up towards his as he says "this asshole" and guides your lips to his. At first the kiss is slow, tentative. Like he'd be asking permission if his mouth weren't already occupied. He's gauging your comfort but he soon finds confirmation when you let out a small whine as you raise to your tip-toes to deepen the kiss.
Like a powderkeg, Frank hauls you closer to him, guiding your bodies back into your apartment with your lips still locked. You're nearly floating, the strength of Frank's grip carrying you into the bedroom where he lifts you onto the bedroom and undresses you as he kisses along your body, telling you how fucking beautiful you are. And throughout it all you hear Frank's plea-- let me love you, let me love you, let me love you-- in the way Frank fills you up slowly, the way he asks "you ok sweetheart?" every time he draws a whimper from you, the way his hand is soft on your stomach as an orgasm tears through you.
And that was it. Not another moment passed that Frank didn't let you know you were his and he was yours.
Not the most storybook love story but it's how I envision it.