Courtney and Scott do NOT belong together
They are both jerks. Courtney's "second virginity" is totally bogus and completely unfair to Scott, who is obviously someone who needs sex in his relationships...but by living with him, she completely deprives him of that. This recipe is only going to lead to him cheating on her.
At the same time, Scott is being awful with his highly chauvinistic attitude, not even wanting to hold his kid, and not sharing one whit in the baby-caring responsibilities. Even if Courtney did allow sex, Scott is doing absolutely nothing to make himself attractive to her.
Courtney needs to move out and see a lawyer and get Scott's paycheck garnished, because that is pretty much all he's good for is making money. They will be a lot happier apart with Scott free to see others and Courtney free to raise her kid in a much more loving environment where her abstinence can be a guilt-free choice and not a source of pressure.