what makes two people fit?

what is it that makes two people fit together physically?
is it how your bodies are built? your relative size to each other?
the pheromones you each produce which happen to mesh together?

as a girl, i know i read a lot more into an encounter than the guy is - and i'm a girl whom most of my friends think acts more like a man than woman where relationships are concerned.

the thing is, i had people i fit with. people i connected with. until they met someone they connected with better. so none of that seems to matter in the long run. or maybe it's just the first inning and i don't know that yet.
 

i've been thinking about this again because i slept with this boy recently. the last time we slept together was an entire age of consent person ago. out of everyone i've ever been with, he's the first boy i didn't regret, and by that same token, one of a small handful of guys i'd wondered what it'd be like to sleep with again now that i've been around the block a few times. it doesn't hurt that he's still very attractive with a very nice body, and we had fun, happy sex back in the day.

it's funny how nostalgia makes caution fly out the window. we had sex multiple times without any protection. i should know and act better, but there's the trust of nostalgia (which i'm sure is responsible for many diseases and progeny out there).

to make matters more tv-worthy, we were out at dinner with his best friend, my college boyfriend, when the vibe first started to manifest itself. i'm sure the diner staff thought it was hilarious how we were holding hands under the table whilst sitting opposite this other guy. i ended up inviting him back to mine, and for the first time in a long time, i felt shy. instead of ripping off each other's clothes and attacking each other, we took things relatively slow. and once we got going, we couldn't seem to get enough of each other. this is something many men have said to me and then proceeded to not get enough of someone else, so i never dwell too much on it. i appreciate its contribution to an all-nighter though.

did this guy and i have a great night because we're fond of each other, have good chemistry, took a trip down memory lane and were relieved to find the other still knew what they were doing - maybe even better - and had the luxury of nostalgia, the chance to compare, and the pride of growth (and thus being better in bed)? or was it something more significant? did we seem to fit because of our relative size and height? because we hadn't had sex with someone we like (physical attraction or convenience does not equate to like) for months?