They will, in 20-25 or so chapter, by the flow we going now. He will propose to Lit during the winter solstice festival which happened after Ruti Arc. As for the kid part, it wasn't explicitly shown but Red did mention that there's going to be a lot of newborns roughly 10 month after said festival so there's hope. As for Ruti response to this, she did have a heart to heart talk with Lit and she's okay with it. Though her real reason for said respond is pretty funny.