Imagine your OTP getting ready for a formal event. Person A's tie isn't tightened enough and Person B fixes it for them. Then Person B pulls Person A by the tie in for a kiss and just as it starts getting good, smirks and mutters that they have to leave. Person A is left with ruffled hair, red cheeks, and a whispered promise of more in their ear.

I don't know anything about writing steamy scenes, so there's only kissing. But it's not very detailed. That's all.

"Do we really have to go?" Sungyeol flops down on the bed. He's wearing a white button-down shirt on top and bright orange boxers and black socks on the bottom. Myungsoo finds the contrast both cute and y. Especially when the boxers rise up to expose more of the pale, long matchsticks Sungyeol has for legs.
Myungsoo snorts, but doesn't say anything. But it's not like he's supposed to. Sungyeol has asked that question so many times since they got the party invitation that it's become a rhetorical question. He finishes tucking his shirt into his pants and picks up Sungyeol's pants from where they had been carelessly dumped and throws them at the other.
Sungyeol snatches the pants out of the air with practiced ease. Mainly because Myungsoo is usually dressed and ready before him and Sungyeol then ends up having clothes (and once a shoe) thrown at him in his boyfriend's attempts at hurrying things along. "I could be doing much more important things tonight."
"Like what?"
Sungyeol pauses with one leg in his pants and locks his eyes with Myungsoo's. "You." He makes sure the word comes out as seductively as possible.
"What are you doing with your face?"
"This is my 'come hither' look," he answers, squinting his eyes like he's trying to send telepathic messages to the other. "Don't act like you haven't seen it before."
Myungsoo turns away and heads to the closet, seemingly uninterested. "Can't say that I have."
"Jerk." Sungyeol goes back to putting on his pants. He's done tucking in his shirt and has moved on to attempting to tie his tie by the time Myungsoo emerges from the closet. "I hope you enjoy sleeping on the couch tonight," he tells the other with a petulant pout. He lets out a short huff as the piece of fabric in his hand refuses to cooperate.
"Just because I insulted your attempt at seduction?"
"Yup." Myungsoo rolls his eyes at how childish his boyfriend can be. "But I'll let you make it up to me," Sungyeol says as if he's used to graciously giving Myungsoo a chance to redeem himself. Myungsoo would laugh if he wasn't so busy scoffing at the ridiculousness of the situation.
"How? By properly tying that tie for you?"
Sungyeol looks down at his tie, the cute little owls on it staring mockingly back at him. "Maybe."
Myungsoo smiles, gesturing for the other to come closer with a curl of his finger. Sungyeol drags his feet on the way over so as not to look too eager. He doesn't want to give his boyfriend the satisfaction of being right. When he gets within arms reach Myungsoo shortens the distance even more with a firm tug on Sungyeol's tie. Sungyeol's hands reach for Myungsoo's waist to steady himself. Once he has, he hooks his forefingers around a couple of the other's belt loops and pulls until they're thigh-to-thigh. He gives Myungsoo a challenging look, waiting for him to make the next move. It's nothing but disappointing when his boyfriend only smirks back and proceeds to untie and then re-tie Sungyeol's tie. His hands don't even shake as they loop and tighten the piece of cloth. He pats it lightly when he's done, his smile now full of satisfaction.
Sungyeol is a second away from whining to get his way when Myungsoo grabs the tie and pulls him down the couple of inches it takes for them to be face-to-face. His lips press against Sungyeol's lightly at first before becoming more insistent. Sungyeol's mouth opens readily for the other's tongue, his hands back on Myungsoo's waist and gripping tightly.
"Now we're talking," he says as his boyfriend leans away so they can both catch their breath. Instinctively, his hands reach for Myungsoo's belt, but the other catches his wrists before he can undo it. Sungyeol looks at him in confusion.
"If we do this now we'll be late," Myungsoo tells him as he puts some space between them. He lets go of his boyfriend's wrists to retrieve his suit jacket laying on the bed. Sungyeol can only stare at him in disbelief as Myungsoo slips on the jacket and walks calmly out the bedroom door with a "come on" thrown over his shoulder.
"You can't be serious."