In this, Alec is a woman to man transexual.
Suggested by: @TheDragonThatStayed
"Izzy, we need to talk," Alec whispered, grabbing Izzy's arm and pulling her into his room.
"Alec, what's wrong? Are you okay?"
Alec looked at the ground, "Honestly, I don't know if I'm okay."
Izzy pulled Alec in for a hug.
"Something happened," Alec said, holding back the tears in his eyes. "Remember how after my surgery, I told you I was male outside, but female inside?"
"Yeah?" Izzy said, becoming concerned.
"I don't know how it happened, but I'm pregnant."
Izzy smiled and let go of Alec, "Alec! That's so exciting!"
"No, Izzy, it's really not. I'm not ready to have kids. I haven't even told Magnus that I used to be female before I met him. He has no idea that I have a uterus inside of me."
"Alec. You're 26 years old, in a great relationship, have me to support you, and I know Magnus would be more than happy when you tell him."
"I don't even know how this happened. Magnus is supposed to be infertile, and the baby can only be his."
"Well, apparently Magnus is special."
"Izzy! You're forgetting something. Magnus has demon blood, it's like I'm having a baby with a demon, the baby isn't going to survive."
"Tessa Gray is fine."
"Her mother wasn't marked. That was the only reason she survived."
"Aw, come on, Alec. This baby was conceived by chance, why shouldn't she survive. Just please, see the pregnancy through, and tell Magnus. Tell him for me, okay?"
Alec took a breath, "Fine, but I'm only doing this because I've always wanted a kid, and Magnus is the guy I want to raise my kid with. And did you just call my baby a 'she'?"
"I really want a niece," Izzy gushed.
Alec rolled his eyes, but gave Izzy a small smile, "Thanks Izzy. I think I'm going to go tell Magnus about this now."
Izzy smiled widely, "Go. I'll cover for you." She hugged Alec tightly and kissed his cheek.
"Thank you," Alec hugged her back and left the institute.
*****
Alec arrived back at Magnus' apartment and walked through the door. Magnus poked his head into the room.
"Alexander? I thought you were going to the institute?"
"Aren't you happy to see me?" Alec asked.
Magnus walked up to Alec and kissed his lips softly, "Of course I'm happy to see you. I was just surprised to see you this early."
"Well, actually Izzy covered for me today so I could see you."
"You just left this morning," Magnus smirked, "Why did you want to see me so bad?"
"I have something to tell you."
"What's wrong, Alexander?" Magnus asked, a concerned look coming over his face. He put his hand on Alec's shoulder.
"I found out a couple days ago that I'm pregnant."
"Pregnant? How is that possible?"
"That's what I needed to tell you. Before I met you, I got reassignment surgery to become male. Internally, though, I'm still female."
"How many weeks are you?"
"About two."
"But, Alexander, I'm a warlock. I'm infertile."
"Magnus, you have to believe me, I haven't been with anyone but you."
"I believe you, you wouldn't ever do that. Plus, I remember what we were doing two weeks ago," Magnus said with a wink.
"I know it's improbable that this kid is inside of me, but I want to see if it's going to really happen. Mags, there's a chance that we're going to have our own child."
"I know, Alexander, I know," Magnus smiled, pulling Alec in for a hug. "I love you. I love this baby, and I want to raise it with you."
Alec pulled out of the hug to kiss Magnus.
"Who else knows?" Magnus asked.
"Just Izzy. She was the only one who knew about my surgery, so she was the first person I told. I know, it should've been you, but I just didn't know how to tell you. She helped me."
"It's okay, Alexander. I'm just happy you told me."
*****
A couple months later, Alec and Magnus went to the silent brothers to make sure their baby was healthy and got surprising news.
"Alexander Gideon Lightwood, you are pregnant with two healthy children," Alec and Magnus heard the silent brother say.
Magnus grasped Alec's hand, "What?" the warlock asked in a surprised whisper.
"Twins, Magnus! We're having twins!" Alec said excitedly.
"Would you like to know the sex?" the silent brother asked.
"No," Alec and Magnus said simultaneously.
*****
At the end of his pregnancy, Alec had to go to a mundane doctor so he could get a c-section. Magnus was with him through the entire surgery, standing by his side in support. After a short amount of time, Alec had a baby girl in his arms, and Magnus had another baby girl in his.
"What are we going to call them?" Magnus asked, the tears from seeing his daughters making his makeup run down his cheeks.
"How about Victoria Marie?" Alec suggested.
"That was fast, how long had you been sitting on that one?" Magnus smiled.
"Izzy really wanted a girl. She's been suggesting names to me since I told her, and I really liked that one."
Magnus giggled, "I love it. Do you have another?"
"She knows we were having twins, so I also liked Elizabeth Nikole."
"They're gorgeous."
"Victoria Marie and Eliza Nikole Lightwood-Bane," Alec said, looking at each baby to try out their name.
"Lightwood-Bane?" Magnus asked in surprise.
"Yeah, you're their father, too."
"What will your parents say?"
"I don't care. They are your daughters as much as mine."
"Thank you, Alexander," Magnus said, kissing Alec's lips.
"You deserve it, Mags," Alec said with a smile.
