Navigator Pressly is the XO and Navigator for the Normandy SR-1. His grandfather served in the First Contact War, which he admits doesn't really make sense since Ashley Williams' Grandfather also served in the war and she is much, much younger than he is. Navigator Pressly is not comfortable with people discussing his age or how he "should be dead". He's been heard yelling, "I'm not that old" on several different occasions. Despite his age, he is loyal to his commanding officer and will set aside her odd behavior to press any and all important buttons that may need to be pushed.
It's been rumored he is in some sort of romantic relationship with the ship's Chief Medical Officer, Doctor Chakwas, though neither person will confirm this allegation.