I think during that scene it crossed everyone's mind but after thinking it through the only reasonable connection would be him being just the husband and not the father. The reason is that Alexis is older than MC and Layla same age as him. Adrianna was also Emily's roommate. His parents wanted Emily to go through with abortion but he was already the father of a 2-year-old Alexis and impregnated Adrianna with Layla at the same time he did Emily with MC? And Adrianna-Emily share a dorm and nobody ever knew? if that's how it plays out to be then it the plot would end up being stupid so I focused on Gabi's husband. Remember when MC sees her talking on the phone at the sports event? She said 'and you left already? Couldn't you just stay a little bit longer?' So there's a high chance he would be the scouter watching the events and just left after that. We also see a picture of Gabi and her husband at her place. It's still speculation though and completely deniable of course just like your scenario. I guess we'll see but I don't think we'll make any progress on that in episode 9.
All I know MC's father could be married with Gabi and we get to choose whether we pull out or not, so she could get pregnant with MC's child and her husband would also be the grandfather and stepfather to his son's child and Adrianna's husband could be MC's father's brother, so Alexis and Layla could be MC's cousins. That's how surprising the plot is so I expect anything at this point
p.s. Incest isn't allowed if I'm not mistaken so that means none of the girls he did anything could be related to him.