Bucky loved him first.
He can't ever have him.
He knows that.
Can't ever throw his arm around his waist instead of his shoulders and peck him on his cheek, as he has done with so many girls before, trying to replace something irreplaceable.
Can't ever take him on a first, fifth, hundredth date.
Can't ever show him of to the world.
Can't ever kiss him, hug him for too long to be considered friendly, nuzzle his face in his hair.
Can't ever take him apart with his mouth, hands, watch, feel his body arch under his own, see his eyes flutter closed or see his mouth open slightly.
Can't ever marry him.
Can't ever spend his life with him, get kids who wear Bucky's smile and Steve's eyes, can't grow old together.
Can't ever have him in the way Bucky wants him the most.
And he knows. He knows he's lucky. Being friends with Steve should be enough, it really should. But he can't, can't think like that.
Can't let himself fall apart for that long.
He knows he's lucky to have Steve. To blame sleeping in the same bed with tangled legs on "it's cold outside" or "your bed is more comfortable than mine". To blame his arm around Steve's thin shoulders when they're outside on "can't trust ya not to run away and start a fight, now can I," or "ain't nobody gonna try something when we're two". To blame his lips against Steve's neck and his arms around his waist, pressed together way too close, when they're alone on their couch in their apartment, on, "it's been a rough day" or "I'm cold, you're warm".
Bucky knows he'll lose Steve one day.
One day, Steve's going to find a girl, fall in love, and settle down.
And Bucky's going to have to watch it happen, pretending like his heart isn't breaking as he watches the love of his life love someone else.
Because there's no one else for him than Steve. He's looked, goddamnit, he's fucking looked.
He's been with so many girls, he's lost count but no one, not one of them, feels the same way against him as Steve does. Has as beautiful eyes as Steve, as pink lips as Steve, and even though they're really pretty and Bucky enjoys being with them, because most of them are really smart and funny, not one of them makes him feel the same way Steve makes him feel.
It scares the crap out of him.
If Steve knew, hell, if Steve knew, he would never talk to Bucky again.
And Bucky wouldn't be able to handle that. He would die. He would die if Steve untangled himself from Bucky's life and left him.
So he needs not to tell him. He really needs not to tell him.
He will go through watching Steve fall in love, secretly, desperately, hoping that it won't work and that he'll be Bucky's again, if that means he can still be by his side.
He'll lose him, Steve will fall in love with a nice girl, settle down, get blonde little kids. And Bucky will have to do the same with a girl who's really smart and funny and who deserves someone better than Bucky, who will always love someone else.
Steve is going to be claimed by someone else, and Bucky won't have him anymore. He won't be Bucky's.
But Bucky loved him first.
He realised how fucking amazing Steve was first, became his friend first, grew up with him first, moved in him with him first, fell in love with him first.
And he won't ever let that go. He'll cling onto it. As he watches Steve laughing with his wife, their kids running around their legs, one thing will go through Bucky's head as he watches them, a quiet kind of breaking inside of him, over and over again, "I loved him first, I loved him first, I loved him first".
She wasn't there when Steve broke his leg, or when he almost died that winter and Bucky cried the entire time, because he really thought he was gonna lose Steve and he was terrified. She wasn't there when Steve's mother died and Steve clinged onto Bucky's hand during the funeral, but clenched his jaw tight and didn't shed a single tear. She wasn't there when Steve finally broke down in the middle of the night in their bedroom and Bucky held a shaking Steve through it and she didn't hang the sheets up in the morning because they were wet with tears. She wasn't there after Steve's fights, didn't clean up the blood from his face afterwards, didn't shake with withheld tears and things she wanted to scream at Steve.
That was all Bucky.
And that has to count for something.
(At least Bucky got to have Steve in some parts.)