This page contains all the information you need on how to have a romance with Ashley Williams.
Securing the Romance
Once you’ve completed the necessary steps to continuing the romance with Ashley which can be found here, How To Start Ashley Romance. From this point onwards, you’ll be able to speak with Ashley aboard the Normandy and by doing so you’ll progress your relationship. Eventually, you’ll meet with Ashley at the Presidium Commons which is located at the Citadel.
Here you’ll want to choose the following dialogue choices to secure your romance with Ashley, “You’re very distracting” followed by “Yes”.
Finally, as you start the mission, Priority: Earth, Ashley will meet you in your cabin and you’ll engage in an intimate moment together