Cheat Codes by Emily Goodwin

Archer has always wanted what he can’t have—Quinn Dawson. Since the moment he saw her, he’s been denying his feelings for her, ignoring the void in his heart he knows only she can fill.
Everything about them was wrong, the kind of wrong that felt so right. But none of it mattered. Not the terrible timing. And definitely not the mess it would create if Archer made a move on his best friend’s baby sister.
It was supposed to be one night, but one night is all it takes to make everything more complicated, and they only have nine short months to sort it all out.
No, none of it mattered. Until it did.