Like the title said for some reason only I can believe my girlfriend thermally expands. Why? I can only imagine it had something to do with my mixed heritage having a Catholic exorcist as a father and a Shinto priestess as a mother... How would that affect anything? Well first let's make sure you understand the concept of thermal expansion. Essentially when you heat stuff it tends to expand, conversely if you chill something it tends to contract. Now onto the start of the story that will eventually explain the second question.
So the date starts at a fine place for a blind date, a nice little restaurant. My date Stella arrived in a somewhat more conservative yet stylish dress which framed her slim frame. We chatted for a bit... more chit chat than anything, ordered our food, and then it felt like we were hitting a brick wall. I didn't have a lot of hobbies and... Well work was steady yet boring, and my side hobby of "exorcising" things felt a little too weird to bring up. Also I tried skirting around the fact that I still lived with my parents... Which felt weird even though we lived in a mostly unused church that was large and had a small Shinto shrine built on the side. I sighed as we all ate our piping hot meals. The room itself was room temperature, but as she consumed the food her body heated up. She changed slowly, but midway through the meal when we talked a bit my eyes went from my plate towards her face. On the way her breasts were in the way and... They seemed fuller and, did her dress always have a cleavage slit in them? In my confusion my eyes lingered and then Stella's eyes narrowed.
"Ugh! What's with all you guys!?!" she huffed as she then got up and started to leave in a hurry. My mind raced as I wondered if she was possessed or something. I got up as well, and got out a 100$ bill from my wallet and put it on the table... Should cover the unfinished meal at least... As I stood up it got easier to notice... she seemed taller too...
I followed her out the door and said "Sorry, it's jus-"
She huffed and said "Quiet, I'm sick of getting to this part of the date and finding out my potential boyfriend just likes staring at my tits!" Then a cold wind blew, I winced, but Stella shrieked a little as my eyes stared at her as she went from a tall curvy woman into... a short cute one. The dress was also more cute and her boots were kinda fluffy.
"The hell happened?!?" I asked
"Wait you saw?"
"So I wasn't just seeing things?" We stood in silence a bit as the wind blew a bit more and she got smaller and cuter as she lost more body temperature "Um... apologies for staring... I was just thinking if my memory was failing me and..."
"Could we get in your car?" Her voice was higher pitched "I'd rather not be shivering to the size of a kindergartener."
A quick car warm up later and Stella was already regrowing so I asked "What's this whole thing? Are you possessed? How'd this happen?"
"Well... I kinda grow a bit when I get hot and shrink a bit when I get cold... As for how this happened? I think I had a weird dream or something and then this all started happening. No one notices anything weird and my clothes change to match. Till now."
"Huh, that's... Haven't heard something like this in any fairy tale or legend... Ever try to get this exorcized?"
"What?! No! It can be fun and I get to shift my body size so I can have fun small and big... Plus There's some fun things you can do with heating certain parts of my body only~" The heater was starting to warm up and she thrust her chest directly towards it and her cleavage grew and grew and grew till she could sit back in her chair and they were still being directly heated.
I blushed and could feel my own secondary sex characteristic grow and asked "Wait! I thought you didn't like your dates being pervy?!"
"Nah, I don't like it when I think they like me for who I am... And then I swell and they just stare at my tits. But you know who I am and considering this is one of my biggest secrets and is a big part of who I am. Well I don't mind sharing~" I turned the heater off, opened a window, and the cold air blasted in reducing her massive breasts to practically nothing. "Hey!" she shrieked yet grinned. "What are you? Some good ole Christian boy who wants that sorta thing after marriage?"
I tilted my head and said "Spiritual, have a bunch of christian values although whether or not the big guy is upstairs is... I'm uncertain. Spirits and weird folk however I'm pretty sure exist. They usually don't do this sorta thing though... Mind if I ask if you came home for my parents to get a look at you?"
Stella blushed a bit thinking I was going a little too fast in the traditional way, but hesitantly agreed... Till she actually saw my place and she grinned wondering who the hell I was exactly. The night air was still cold so she shrunk a bit while we walked as I explained my heritage- "You're a super mixed-race exorcist! Dual wielding rosary beads and talismans!"
"I've got a niche little youtube channel about exorcism... and I outgrew that phase awhile ago." I explained as I rang the doorbell. My mother was the one who answered.
"Ah, Hello. You brought your date home an- Oh she looks so young!" She looked at me accusingly of picking a date with a minor.
"She's special, I'd like you or dad to look into her condition." I asked
Mom sighed and said "Well come on in, make yourself at home miss... I'll just be a bit." Waiting at one of the old church pews Stella seemed to fidget a bit. Perhaps she was a somewhat unfaithful Christian and was wondering if she should pray or something?
Mother came in with a Priestess gown and a heater as she said "I'm sorry this old place must get a little chilly. My husband doesn't like to use the ac to heat this place." Then she turned on the heater.
I said "I think the heater might actually help show the issue."
In a way it did as the shrieks started happening. My father hearing the commotion came in and asked "What-" then saw me with my eyes closed, face covered and turned... Meanwhile my mother was trying to get to Stella and shield her body which was growing while her clothes weren't for a change. Stella was also flush red- he closed his eyes and said "Better pray boy. Lest ye go to hell." then walked out.
With the heater off and a fan blowing on Stella she shivered a bit as she preferred her clothes a bit loose than too tight when sitting down.
Dad came back as Stella asked "What the hell happened with my clothes?"
Father said "I'd not invoke that name too much. Also this place is twice sacred! I'm more surprised that little trick of yours works at all!"
My mother nodded "The source is contained within you... While in a place like this it should probably only affect you."
"It'll take a bit to get you exorcised of it. Time and preparation but it can be done!" my father added
"What?!? I don't want to be exorcised!" Stella exclaimed "It makes me special!"
"It marks you for damnation!" my father said "Think about that before passing on with a taint bound to your immortal being!"
I sighed and said "I think I'll take Stella home. This is probably a bit much for her and we can't do much for her right now anyways..." Thus I brought her in the car. On the way back I said "Don't worry about that damnation thing... Practically everyone's going... there... to him." some more silence "Well... Um... sorry if all that got a little intense." There was a lot of thinking and when I got to her address "Sorry again... If you want to get that exorcism-" I took out a small business card from the glove compartment.
"Is this your way of giving me your number?" Stella asked
"What?"
"Is this your way of asking for another date?" She clarified a little hope in her voice
"I thought you were... overwhelmed and done..."
"No! I was worried because your father was so... Hell to thee! You couldn't date me or something."
"No, um... Yeah no. If anything he probably think Mom's going there. He'll probably warm up, and we can figure out what exactly your bound with and whether or not the old bible says it condemns you or not. Still, I know it probably hasn't done anything to you, but invoking something so old and dangerous... I'd just not do it a lot. "
Stella chuckled and said "Ok then! We'll got on lots of dates then!" She then went back to her home with her slightly baggy dress on.