This could work

                                    

                                          
~~Eridan~~
                          
Eridan sat at his hive, not being able to bring himself to leave and go to school. He had to much on his mind. If he had gone, he would've probably had a panic attack. 
                          
He sat in a chair, staring at the wall. He had a lot to think over. Why not address the first?
                          
Sollux. 
                          
Sollux captor.
                          
He was a sweep older than eridan, so he was in the grade above him. Mustard blood. Tall. Hot. Wait, no, not hot. Eridan had mixed feelings about him. He didn't seem to be the type to advance him and try and kiss him after he had just witnessed the whole Karkat thing. 
                          
He had a feeling Sollux was very red or very black for him. He felt kind of bad for just leaving Sollux there like that yesterday for some reason.
                          
'He was touching your fins! you shouldn't be sorry about leaving him there.' He thought to himself. 
                          
But no matter how hard he tried, he couldn't deny that he actually liked it. But he couldn't show it. He couldn't give in to Sollux. But he felt he had to apologize for just leaving. He decided he'd go back after school ended. 
                          
The second thing he needed to address. 
                          
Karkat. 
                          
Karkat Vantas. 
                          
Eridan truly loved him. Karkat was short, skinny, cute. He never would've expected him to go off with a girl. Especially Two girls. 
                          
But that's when Eridan started thinking that maybe he didn't do that by choice. When he had turned to see that, a flicker of fear and discomfort was in his eyes and body language. 
                          
Eridan sighed to himself. 
                          
'You idiot. That was probably just a prank that you weren't supposed to see. You need to see Karkat again.'
                          
He decided he would head to Karkats hive after he apologized to Sollux. He laid back in his chair and decided to take a nap. 
                          
-----
                          
Eridan woke up about the time school would get out. He decided he'd wait about a half hour before going to see Sollux. The time passed quicker than it felt it would, and he decided to go. 
                          
It was a hot day, so he left his scarf and cape at home. He swam out of the ocean, and rolled up his sleeves when he broke the surface. 
                          
He arrived at Sollux's hive, his hair still slightly wet. He ran a hand through it, and knocked with the other. Sollux opened the door, seeing him and smiling. 
                          
"Sup, ED."
                          
~~Sollux~~
                          
Sollux stood at the doorway, looking at Eridan. He smiled to himself. He felt a slight headache come on, and tried to ignore it. 
                          
It seemed every time he thought of doing anything to Eridan, he got these headaches. He decided to just shrug it off as he let his thoughts consume him. 
                          
"I just wanted to say sorry for just kinda leaving yesterday..." Eridan said, itching behind his head. 
                          
"You know how you could make it up to me?" Sollux purred. 
                          
Eridan dropped his arm by his side, rolling his eyes. "How?" he sighed. 
                          
Sollux grabbed Eridan's arm, leading him in. He felt Eridan bring his other hand up to try and pry Sollux's hand off his arm. 
                          
"Sol, let go, what're you doing?" Eridan said in a panicked voice. 
                          
Sollux lead him upstairs into his room, slamming the door shut. 
                          
"Sollux." Eridan said, in an even more panicked voice. 
                          
Sollux slammed him up against the wall. Eridan yelped. He looked into his eyes, smiling. 
                          
Eridan looked quite nervous. Sollux brought Eridan's hands up above his head, holding them with one hand. He took off Eridan's glasses. 
                          
"Sol, come on, give them back." Eridan whined, struggling against Sollux's hold. Sollux threw Eridan's glasses onto his dresser. 
                          
"Nah." Sollux said. He released his hold on eridan, letting his psiioniics take over. He held eridan against the wall with his mind, and let his powers lift the bottom of Eridan's shirt. He brought it up off if Eridan's torso. 
                          
"Mm, hottie with a body." Sollux purred. 
                          
Eridan blushed violently, not saying anything. He looked right at sollux, a mixture of fear and a bit of lust in his eyes. Sollux walked closer to him, putting his hands on Eridan's bare chest. 
                          
"Hmm? cat got your tongue?" Sollux whispered into Eridan's ear. He felt eridan tense up. Sollux chucked and nibbled on Eridan's fin. 
                          
Eridan sighed out of pleasure. 
                          
"Sollux." eridan whispered. "You n-need to stop." 
                          
"But you like it~" Sollux said in a seducing tone. 
                          
Eridan made a whining noise in his throat. "S-still." Eridan said in a slightly higher tone than he normally speaks.
                          
"But we haven't even gotten to the fun part yeeeeeeeet." Sollux pouted. He put a finger in a belt loop of Eridan's jeans. Eridan squirmed slightly. Sollux pulled down slowly. 
                          
"Sol, no. I-I can't." Eridan squeaked. 
                          
"Why noooooooot?" Sollux whined. 
                          
"B-because I have a m-matesprit." Eridan stuttered. 
                          
"But he cheated on you. You can have me now." Sollux said, running his hands up Eridan's chest. He put his lips on Eridan's neck, and kissed him. 
                          
"I was g-gonna talk to him about it." Eridan said, his voice getting higher as Sollux kissed more down his neck and down to his chest. 
                          
"Talk to him later, play with me now, baby." Sollux breathed against Eridan's skin. 
                          
"S-Sollux~" eridan moaned as Sollux sucked on is skin. 
                          
"I have too. M-Maybe later." Eridan said. Sollux looked eridan in the eyes, and at his lips. 
                          
"Fine. But you have to promise." 
                          
"I'm not promising anything."
                          
Sollux slammed his lips against Eridan's. He felt eridan squeak in protest, but it wasn't long until eridan was kissing him back. 
                          
~~eridan~~
                          
Eridan kissed Sollux with passion. 
                          
'What the hell are you DOING?" He thought to himself. But he couldn't stop himself. Sollux released the hold he had on Eridan's hands, and eridan brought them down to pull Sollux closer. 
                          
'You need to stop. You have a matesprit.' eridan eagerly thought to himself. 
                          
"Gog," eridan said between breaths, "I fuckin hate you sol."
                          
"I bet I hate you more, you piece of shit." 
                          
Eridan smiled, removing Sollux's shirt. 
                          
At least he was sure that Sollux was black instead of red for him now. This could work. 
                          
Eridan felt Sollux putting his hands on the sides of Eridan's hips, sliding his pants down. Eridan undid Sollux's, removing them. 
                          
Well. 
                          
You think of what happens next. 
                          
((Sorry I had to do that I don't feel like writing smut rn
                          
Don't hate me for that))