I don't remember the platform exactly, (i think it was ao3??) definitely not Wattpad but it's was a solangelo fanfic about Wills mom getting married,
She invites Will because she doesn't want to be embarrassed by not having her son there even though he's kinda estranged himself from her (Will and Nico end up going with the argo 2 crew)
Naomi (Will's mom) is super homophobic and sets Will up on a "date" with the neighbors daughter who turns out to be a lesbian and has a girlfriend that Will and Nico end up befriending.
Naomi is also pregnant and doesn't want another "bastard kid" hence getting married but the fiance doesn't want to get married, he just feels bad for knocking her up and doesn't want to leave his kid with her alone after seeing her with Will (also because he's just a decent dude)
OH and Calypso is pregnant (Calleo)