Steve wakes up first. He needs a moment to remember why he's not in his bed but then a smile creeps onto his face when he does. He turns his head and sure enough, there's Tony by his side, still asleep.
He looks younger like this, more relaxed than Steve ever sees him during the day.
Steve reaches out to brush some of the curly strands from Tony's forehead, smile growing wider when his boyfriend's face scrunches up slightly at the touch. He can't help it, he slides a little closer and gently presses his lips to Tony's nose.
He keeps that up for a while, kissing every part of Tony's face he can reach until warm brown eyes flutter open and focus on him.
And then, to Steve's surprise, Tony's cheeks take on a soft, rosy blush. It's by far the cutest thing he's ever seen and Steve is mesmerized.
“Awesome way to be woken up”, Tony mutters. The blush on his cheeks actually gets darker, and Steve reaches out to trace it with his fingers.
After everything he's heard and learnt about Tony, he didn't think blushing would be something Tony would do.
It's not a one-time thing, Steve finds out.
He comes down to the workshop in the evening to fetch Tony for dinner. The whole room is lit up in soft blue and Steve stops, stunned, taking everything in. He knows what he's seeing; this is Tony's brilliant mind at work, creating ideas that will form the future.
“Wow”, he breathes out and Tony whips around, smiling widely when he spots Steve.
“Hey soldier”, he says. Gestures for Steve to come closer. Of course Steve follows, wrapping his arms around Tony's waist to pull him against his chest, head resting on the brunet's shoulder. “Wanna know what this is?”
Steve nods. He loves to hear Tony talk about his inventions, loves the way his lover lights up while doing so, how he explains everything with so much passion. It's breathtaking, to hear how Tony's mind works, what he creates and Steve adores this man so much, his heart is threatening to overflow with all the affection he holds for Tony.
It takes a good ten minutes before Tony stops talking, brown eyes bright and happy. He cranes his neck and gives Steve an expectant look.
“You are incredible”, Steve whispers truthfully. “Tony, this is brilliant. You really are the most amazing person I know.”
And oh. There it is again.
Tony's cheeks flush immediately at the honest compliments and he turns away, clearing his throat. He's embarrassed, Steve can tell, and he wraps his arms tighter around Tony.
“You are, sweetheart”, Steve assures him. “Also the kindest, most generous man I know. I love you.”
The blush darkens, goes all the way down to Tony's neck and Steve follows it with his lips.
They are out together, walking home from a nice dinner at Steve's favourite restaurant. Since they've only been dating for roughly a month, Steve isn't quite sure if he's allowed to hold Tony's hand just now.
He isn't sure if Tony wants to risk being seen.
But they walk close to each other, Tony talking animatedly about another project he's going to tackle next and Steve listens attentively, sometimes throwing his own ideas in. Tony seems so pleased and happy when Steve does that, his smile so brilliant it's blinding.
Their hands brush and while Steve doesn't think much of it, Tony suddenly stops talking and-
Steve's heart skips a beat at the cute blush that spreads across the brunet's cheeks once more. It's really the most endearing sight he's ever come across. Steve didn't think Tony would be one to blush; the guy has sex tapes on the internet and about zero shame.
But here he is, the most adorable blush Steve has ever seen dusting his cheeks and Steve really can't help himself. He pulls Tony in to kiss him, watches with wonder and slight satisfaction how the blush darkens and then slides his hand down along Tony's arm, intertwining their fingers.
He doesn't let go and the blush on Tony's cheeks doesn't go away.
The others notice the blush during movie night.
As always, Steve and Tony are in each other's space, cuddled up against each other, being the “disgustingly cute couple” as Clint said it so beautifully. Natasha passes the popcorn bowl to them and Steve reaches into it without really looking, eyes drawn to the TV.
He only looks when his fingers brush against warm skin. Tony stirs besides him, moves to hide but he's not fast enough.
“Holy shit.” That's Clint.
“Is that-” Bruce sounds as stunned as the archer.
“Are you blushing?” That's Clint again and Tony groans, hiding his face against Steve's neck.
Natasha meets his eyes. There's a soft smile playing over her face and she nods to Tony. “That's actually a pretty cute look on you, Tony”, she states and everyone agrees. Tony lets out another groan like a dying animal and Steve snorts. What a bunch of ridiculous people he's found for himself.
Once the attention is diverted again (by Thor using the moment to snatch the bag of treats Clint brought for himself, effectively starting a pillow fight), Steve curls more around Tony and brushes his lips over his boyfriend's ear.
“You do look adorable when you're blushing”, he whispers. Tony huffs against his skin and slaps his chest.
Steve grins. “Make me.”
Steve has his head propped up in one hand. With the fingers of the other, he's following the lines of muscles on Tony's back, traces over his lover's spine and plays with the short, dark curls in the back of Tony's neck.
He leans in closer, nuzzles Tony's cheek before kissing it. Tony sighs into the pillow, stirring lightly.
“Why are you always so chipper in the morning?”, the brunet grumbles, his voice rough from sleep – and from having moaned Steve's name last night. “That shouldn't be possible.”
Apparently Steve is feeling particularly sappy this morning because he answers: “How could I be in a bad mood when I got to wake up next to you?”
Predictably, Tony snorts and rolls his eyes, but the smile he gives Steve is full of love. “You are a big marshmallow, Steve Rogers.”
Steve kisses him.
“I'm your big marshmallow.”
Tony makes a soft noise at that. Steve feels his heart pick up speed and watches as the blush spreads across Tony's cheeks again. He will never tire of this sight, that much is for sure. Steve thinks that he's already a bit addicted to seeing Tony blush – to making him blush.
“I love you”, he confesses into the soft, dark curls of Tony's hair, smiling at the way this phrase warms his heart. Under the blanket, Tony slides his hand into Steve's, squeezing lightly.
“I love you too.”