Mystery Ex-Girlfriend
Mystery Ex-Girlfriend was an un-named 23-year-old female YouTuber Greg dated in-between Shiloh and Adrienne.
Info
When listing all of his relationships during his YouTube career, Greg lists a 23-year-old after Shiloh and before Adrienne. He notes "a relationship with a popular YouTuber [I] never announced." (Source)
There is not a lot of information about this girlfriend because after his first major break up with Shiloh, Greg began dating privately. The only time he talked about her in a video was in "She Wanted My Body, Not My Heart", which was uploaded August 24, 2011 on his Speaks channel. The description to the video read "Cry, cry, cry... and then... hopefully heal ~ that's been my life as of late." In the video, Greg says right before filming a video with BlackBoxTV, he was dumped by someone he was not officially dating. He sucked it up, filmed the video, ate at Denny's, then cried on the highway. Than came home and tried not to cry in-front of his roommate, Cyr. He finished his night by crying in the shower and finally went to bed at 5 a.m., still crying. The following morning he talked on the phone with the ex-girlfriend and realized that they only wanted sex without love, which he does not believe in ($ource)
In Adrienne's leaked email, she talks about how Greg was upset over an "e-fling" he had with a YouTuber that propositioned him for a threesome.
Speculation
The only female YouTuber that people speculate could have been this ex is MissHannahMinx as she was 23 at that time.