Because gratuitous sex and/or rape scenes don't manifest themselves into existence. They're usually built to cater to someone in power behind the scenes personal sensibilities. Actresses have spoken on this reality, and that's immediately what my mind drifted to as I was watching.
The scene just felt out of place to me. *shrug*
The dynamics between Nick and Eden were portrayed in a way that more than conveyed what the reality of their sex life would be. It couldn't have been made any clearer, especially once they brought out the sheet with a hole in it. Plus, we already saw how he was with June that first time..,