Evelyn and Isabella will have an optional NTR path, depending on how you treat them.
For Evelyn's path, I plan to make it so you have a choice to be with her friends, but in doing so you risk losing her.
Isabella's story will have a sort of "rival" character, who's a childhood friend of her, that Isabella doesn't see as a potential partner at all, unless if the MC starts to mistreat her.
As for Jessica she will make an ultimatum after the MC is unable to please her, forcing you to either leave her or become a cuck.
Roxanne she will be with other guys at the start no matter what and then later split into either romance or cuckold.