Little!Alec and Others Adventures

4 Months In and Little!Alec finds out

Lydia has reached her fourth month of pregnancy, more specifically the sixteenth week, and her morning sickness is much better. She's looking in the mirror in her bedroom at the baby bump forming on her previously flat belly. She rubs it as Magnus walks in. "Lydi- Oh sorry." "Magnus! Come here!" She's in her bra and a pair of sweats, she's been hiding the bump until now. He approaches her and smiles as she frames her belly. Magnus runs a hand over it. "Look at that. Are you curious?" "Of course I am, but I want to wait." "Oh I came to tell you that Alec woke up feeling little and I wanted to warn you." She nods. "Time to tell him?" "I would think so. He's about four so maybe we can tell him about his new sibling then take him to the park to run around?" "Let's do it." Magnus nods and goes to Alec in the living room.
Lydia walks in and sees Alec and Magnus playing together. Alec looks at Lydia, not noticing her belly yet. "Mama!" "Hi honey. Papa and I want to talk to you, okay?" "Kay!" Lydia gets closer and Alec can see her belly better. He looks at it. "Mama, why your tummy big?" She smiles at the curiosity. "Mama has a baby growing in her tummy." Alec gasps and looks again. Magnus takes Alec's hand and puts it gently on her swelling belly. He smiles as Alec just moves his hand a little. "Excited?" Alec nods and gives Lydia's belly a kiss. Both adults smile. "Hi in there." "You excited to be a big brother?" "Yeah!" Magnus laughs a bit. "I'm glad that he's taking it well." "I knew he would. Wanna get ready to go to the park?" Alec nods and gives Lydia's belly one more kiss. "Papa less go get ready!" Alec goes to the nursery and Magnus trails behind. "Take your time." Lydia goes back to her room to get dressed.
By the time Lydia returns to the living room, Alec is in his tiny form and fully dressed. He smiles at Lydia and hugs her leg. "Hi sweetie. Ready?" "Yes!" Magnus takes one hand as Lydia takes the other and they walk to the usual park. Magnus makes Lydia sit on a bench and relax as he starts to chase Alec. She smiles and watches them run off. Lydia pulls out a book as she hears someone call her name and sit beside her.
"Lydia? It's been a while hasn't it?" She turns to see Leslie and Mark, the couple that her and Magnus encountered the last time they brought Alec as a toddler to the park. "Leslie, Mark. Yes it has been. How's your daughter?" "She's good! How's your son? We're so sorry about her upsetting him last time." "Don't be she's just a child." "I see that you're expanding the family." Lydia smiles and rests a hand on her belly. "Yes we are. I'm four months along." "Boy or girl?" "We decided to have my sisters learn and arrange a gender reveal party since they've been asking me like crazy to let them do so." It's almost true, except Clary and Izzy are not her sisters. The couple nods in understanding and Magnus approaches them, Alec not with him. Lydia raises an eyebrow. "Where's my baby?" "Relax. He's playing right there." He points to Alec playing with a couple kids and Lydia sighs in relief. Magnus pets her hair and hands her a water from the diaper bag. "Stay hydrated. I know you're not drinking enough and it's what's best for the baby." "Don't tell me what to fucking do, Bane!" She looks furious, then two seconds later she slaps her hand over her mouth and looks like she might cry. "By the angel Magnus I'm so sorry I know you're only trying to help but I'm such a bitch!" Magnus smiles, it's not the first time her mood swings have caused her to lash out. He sits beside her and hugs her. "No I deserve it. I should watch my phrasing." Lydia wipes her eyes and sighs. "I'm going insane..." "You know the mood swings will pass, darling." Leslie smiles. "You should have seen me with Jessica. I threw a knife at Mark once because he bought the wrong brand of water." "That's nothing. I bought the wrong ice cream flavor and I instantly regretted getting Lydia archery lessons." Magnus actually made a comment about her not going on missions anymore and she grabbed Alec's archery equipment, shooting an arrow near Magnus's head and saying that she can still kick ass, but the mundanes didn't need to know that. "It was your fault anyways. You got my least favorite kind!" The couple and Magnus chuckle at Lydia's faked frustration.
The four quietly chat until Alec runs over to Magnus and Lydia, crying a little bit. Lydia opens her arms to him and he pushes his face into her side, minding her belly. "Mama I wanna go home!" "What happened, honey?" She can smell that he needs a change and knows the others can too. "A-A kid push me on the floor an I try get up an he push my tummy an I go potty an-an he laugh..." Lydia pets his hair and attempts to soothe his cries. Magnus grabs the diaper bag as he brushes the dirt off of Alec's shorts. Jessica runs over. "You 'kay Alec?" He continues to cry and shakes his head. Magnus looks at the mundane child. "Jessica, sweetie, did you see who pushed him and was mean to him?" She points to a kid who's walking to his parents. Magnus nods and lifts Alec into his arms, minding not squishing his messy diaper against him. Lydia looks at him. "Magnus?" "I'm only going to talk to them and then we're going home. I'd rather Alexander be home and happy than outside and upset." Lydia nods and says her goodbyes to the other family, following closely.
The kid is talking to his parents about something as the warlock approaches them, Alec still crying. "Hello, I believe your son owes mine an apology." "What? Our James would never do anything bad. You must have the wrong child." Lydia steps forward, rubbing her belly unconsciously. "We have our son and another child as well telling us that your son pushed Alec twice and laughed at him." The father looks at the boy. "James? Is this true?" James refuses to look at his parents. "He's a baby what does he know?" The seven year old crosses his arms. Alec cries a bit louder. "I not a baby!" He buries his face further in Magnus's neck and Lydia pets his hair. "Shh sweetie it's okay we know you're not." The mother of the mundane child looks angry. "James. Apologize to this boy." "No! He says he's four but you can smell that he pooped his pants!" The mundane parents look at Lydia and Magnus for any explanation. "Alexander has health issues so he cannot help it if he wears and uses diapers still at age four, and from what we heard you pushed him in the stomach forcing him to use his diaper." Lydia looks pretty pissed, hating to hear Alec crying. She takes him into her arms and holds him close, minding her belly and his slightly full diaper. The mundane father looks at the family in front of him. "I am so sorry for what he had done to your son. I can assure you someone is in a lot of trouble when he gets home." James pouts at his parents and lets his dad take him to the car. The mother clears space on the bench beside her. "Here. You should change him quickly before he gets more uncomfortable or even a rash." Lydia nods in agreement and thanks the woman, who also helps cover Alec as he gets changed. He stopped crying and lets Lydia do what she needs. Once he's clean, he kisses her belly and hugs her. "Tank you, mama. Tank you, wittle bwover or sister." The adults smile at his sweetness and Alec turns to Magnus, lifting his arms out to him. Magnus pulls him close. "Tank you, papa." "You're very welcome, sweetie. Thank you so much ma'am. I wish you and your family a good rest of your day." Magnus grabs the diaper bag as Lydia disposes of the messy diaper. She thanks the mundane woman and holds Alec's hand when Magnus sets him down on the ground.
Once they get home, Magnus decides to keep Alec small until it wears off. He seems unfazed by staying in his toddler body and jumps around a bit, being careful around Lydia. She sits down and rests a hand on her belly, stroking it softly. "I can feel slight movement meaning someone is awake from all the excitement and I'm going to have to pee soon." Magnus smiles. "Have you felt any kicks from the outside yet?" "No not yet, but they're definitely a shadowhunter I can tell you that. Hey, you taking residence in my uterus, you're not in a demon so stop fighting you hear me in there?" Magnus chuckles softly. "Imagine. Five more months." Lydia nods and sighs and lies down on the couch while the baby moves inside her, the movement being a bit visible to Magnus as she strokes her belly to soothe the unborn child.

"Fuck, I'm gonna be huge."