Author's Note: I wrote a thing for the headcanon! Hope you like it! Tell me what you think! :)
Disclaimer: I own nothing. Characters are all owned by the magnificent Cassandra Clare.
Alec smiled as he felt the Warlock's soft hands tugging on his raven black hair. He ran his hands down Magnus' warm back as the taller man pressed his soft, eager lips to Alec's. Magnus moved his mouth so he could press kisses to the Shadowhunter's defined cheekbones. Alec found himself lifting his head so his boyfriend could have access to move his lips down to the Shadowhunter's neck. Magnus starting sucking and nibbling, wanting to leave his mark on his lover. Alec gasped and slipped his arms down around Magnus' waist.
Before Alec could think, the Warlock's lips were pressed ferociously to the younger boy's. Then, he felt Magnus suddenly very closely pressed against his own body. Somehow in all of this, they had both managed to lose their shirts. Alec became increasingly aware of the fact that he could feel the Warlock's bulge against him. The Shadowhunter made a disgruntled sound in his throat and before he was aware of what was happening, he found himself pushing Magnus away. Alec took a ragged breath and looked up at his very confused boyfriend. The teenager saw a mixture of emotion in Magnus' expression: fear, confusion, apprehensiveness, and many more.
The Warlock asked, fear shining in his usually expressionless eyes. "Alec, did I do something wrong? I'm so sorry. I was moving too fast, wasn't I? I'm really sorry."
Alec looked up at his beautiful boyfriend, who was currently void of makeup. He had left his hair down today because he knew how much Alec loved it. The Shadowhunter's heart was pounding like a loud, obnoxious, bass drum. He realized he was breathing harder than normal. He moved his gaze down to the floor. He nervously pulled on his sweater, unconsciously hiding his hands in his sweater paws. He looked at Magnus again and decided his boyfriend deserved to know the truth. "I -um," he stuttered, "It's not something you did, Magnus. I just-" He broke off and shuffled anxiously. "I d-don't really know how to say this…" He took a deep breath and saw Magnus' expression change. "I don't really want… that." He paused, noticed the Warlock's confused look, and continued, "I'm -uh- not really -I don't want to have sex." He exhaled a breath he didn't know he was holding in. "I'm sorry, Magnus. I love you, but I understand if you don't want to be with me because of this. I am really sorry." Alec waited and looked down again.
Alec felt a familiar hand lift his chin delicately so his blue eyes were looking directly into the greenish-gold ones of the Warlock. "Alec, I'm the one who should be apologizing to you. I was practically throwing myself on you. I'm extremely sorry. Darling, I love you for who you are, not for the prospect of sex."
Alec still felt bad. "I just-" He took a nervous breath, "I know that you do like sex and I just- I can't," he looked into Magnus's gorgeous shining eyes. He felt dread for what he expected was to come.
"My Alec," Magnus looked directly into his own blue orbs, "darling, I don't need sex. I need you." The Warlock took Alec's hand and took a step closer to enfold his Shadowhunter in his comforting arms. Alec rested his face in the crook of his boyfriend's warm neck. He inhaled the familiar scent of sandalwood and smiled as he hugged the Warlock closer. "I love you, Alexander. More than anything. Including sex."
The teenager chuckled slightly and replied, "I love you, too, Magnus, You mean the world to me. I just don't want to deprive you of-"
"Stop talking, love. You could only be depriving me if you didn't let me be with your beauty, okay? I love you, Alexander." Magnus leaned down slowly and planted a chaste kiss on his mouth, causing the boy to blush slightly and smile.