Nathan became friends/close with Elaine when she was on the side of the road crying about how bad her relationship was with her father and sister. they eventually started to fall in love, and Elaine got pregnant unexpectedly. and that's how Mila was made and how Elaine moved in with Nathan.

Nathan never really dated anyone before Elaine, so she was his first love.
when he was young, he decided to focus on college, then his career in business and investing stocks instead of dating. and even once he was successful, he hadn't removed his focus from work. #thesims4 #sims4

Elaine's father became really distant towards her and her sister once their mother died. he even went as far as moving on to a young woman almost immediately after their mother's death. Elaine's sister even became distant and mean, so Elaine never really had anybody besides Nathan. #thesims4 #sims4

Elaine and Nathan have only really had each other since getting married since neither of them had friends, and Elaine's family has been distant and bad to her.
it even goes as far as them being the only ones getting each other winterfest gifts because Elaine's family never sends anything. #thesims4

Nathan did offer housekeeping and babycare to Elaine, but she refused, so instead, Nathan decided to stay home from work or work from home as often as he could to help with Mila and make sure Elaine wasn't getting too stressed out taking care of Mila and doing her uni work.

The twins Adelaide and Rosalie were a planned pregnancy on loveday, unlike Mila, who was unplanned but still loved and accepted immediately by Nathan and Elaine. it was hard for Elaine to have Mila so young because she had to go to university and build her career whilst having a young baby. #sims4

Also Kaiser has to get married soon if he wants this inheritance money from a distance relative but he doesn't know anyone else yet and he doesn't think Micah will say yes if he asks her to marry him so he's ultimately at a halt in his life romantically and he hates it cause he's a love bug sim.

I'm not sure how they'll progress from here because they definitely have a lot of love for each other as coparents, but it's not clear if there's even any romantic feelings left or if the relationship window has closed between them or not. we'll just have to see as time passes.

soo cuteeee <3 i can't wait for my sim to have her baby omgg

Kaiser, their roommate, and Carter's best friend, has a crush on Micah and is more than willing to help her raise the baby, but she doesn't know that because Carter would lose his mind if he found out about it. kaiser flirts with Micah to show his feelings, but she's been oblivious to them so far.

A little back story
Micah is pregnant by Carter, and she had a crush on him long before they even slept together. Carter doesn't think he's ready for a child. therefore, he doesn't want their baby even though he's been so nice this entire pregnancy and told Micah he'd be there when she gives birth.

I'm gonna take that one like as a yes :3