Dating Sam would include:
Always hearing Dean say one of two things, "Go get you some Sammy!" or "God, get a room."
Wearing his flannels to sleep in or to lounge around the bunker in
Sharing interesting facts after getting caught up in some lore
Him getting you to try new, healthier foods
Going on morning runs together
Cuddles on rainy days while sipping on coffee
Reading a series of books together and freaking out together when something amazing and shocking happens.
Protective!Sam coming out to play when a jerk at a bar doesn't know when to quit
Him afraid to get too close because he's afraid to lose you like he lost Jess
Leaving flowers on Jess's grave together
Him being very dominant and passionate in the bedroom
Begging Dean together to get a dog
Puppy dog eyes that cause you to melt
Running your fingers through his hair
Him reaching you things off high shelves
Being carried over his shoulder or bridal style
Him comforting you on bad days
Being total dorks together
Long hugs
Large hands swallowing yours when holding hands
Binge watching an entire TV show series together on Netflix
Hugs from behind
Pranking Dean
Slow dances in the bunker
Him apologizing relentlessly after an argument between you two
Breaking up fights between Dean and him
Calling him moose just to annoy him
Him teasing you by holding objects up high so you have to 'reach for it'
meeting while he was on a hunt with his brother, dean. dean suggested they could stay in town for a few more days.
he was unsure, at first, whether or not you would even be interested in going on a date with him
but dean convinces him to ask you out
"if it goes well, it goes well. if not...well...what do ya have to lose?"
your first date was awkward, to say in the least. you could tell he hadn't been on one in a while, but you didn't bring that up.
but towards the end, when he was walking with you through a park you suggest you visit, something sparked. you really hit it off.
every date you had after that topped the one before it. not in what you were doing, but each time sam went out with you, he fell in love a little more each time.
he officially introduced you to dean after two months.
"sam told me you like pie, so i made you some apple and cherry-"
"sammy, if you don't marry her, i will."
the first time you stayed the night, you just spent the night cuddling.
sammy's the big spoon most of the time (because he is a literal sasquatch)
but that's okay because sam likes being able to wrap you up in his arms
you steal his shirts a lot (who wouldn't oml)
"baby, have you seen my red fla-"
"i can't help it! your shirts are so comfy and huge and soft and huge!"
"hon you said huge twice."
"i know what i said."
but he doesn't mind, because he loves to see you in his clothes.
dean would occasionally get sick of you two
"can you two go make googly eyes at each other somewhere else?"
the nicknames were endless. on your end, anyways.
"moosey." "beanstalk." "babe." "baby." "moosepuppy." "pup." "sweetie." "honey." "samsquatch." "bubs." and so on and so forth.
you found out about the supernatural the hard way:
castiel appeared suddenly in front of you, scaring the crap out of you.
"holy crap! who the hell are you?!"
"i'm castiel. i am an angel of the lord."
"saaaam!"
sam tried to break the news to you gently.
after you'd gotten used to the fact that monsters and ghosts and such were real, you'd asked sam if you can join him on a hunt.
"no way in hell, shortstuff."
you quickly learned that he wasn't gonna budge on that.
so you helped with research from the bunker
sam became extremely protective after you learned what he did for a living.
he wouldn't let you go out alone
or stay home alone without calling or texting every few hours.
he taught you their codewords in case something happened.
"something's stuck on my shoe." "funky town." etc.
you never needed to use them, thank chuck.
every time he and dean came back from a hunt, you'd have a warm home-made meal waiting
"i'm telling you sammy, she's a goddamn keeper."
"i know she is."