The relationship didn't last outside the house however, and the pair went their separate ways after just three months - that is, until they were forced to come face to face in the show's current season, seven-years later.
Drew was up to his old ways yet again, hooking up with a fellow housemate, this time named Sam.
This led to some uncomfortable interactions with his ex, Tully, who entered the house just as Drew and Sam's romance kicked off.
"I kinda wish he [Drew] wasn't in the house," Tully admitted to New Idea following Monday's eviction.
"If I had my way, he wouldn't have been there.”
Gone were the days of the former couple's sweet behaviour toward one another, their affection replaced with angry outbursts - many of which weren't even shown to the public, Tully claims.
“It felt like I couldn't do or say anything without him snapping at me, blowing up at me and storming off,” she revealed.
“I had it pretty rough the first two weeks with him... I think they were trying to give him the nice guy Casanova edit for his showmance with Sam.”
"I was hoping that I get a little bit more of my own journey without the old ball and chain, but that was not to be.”
Sam has since been evicted, and it didn't take long for her to come out swinging.
She claimed Drew lied and “played” her during their TV relationship – but whose side is Tully on following her exit?
“I know better than to get involved with my ex’s business, I think that's between them,” she laughs.
Tully added that her second stint in the house saw her being more “conscious” of how her actions may be edited and made sure to “watch her tongue” more closely than she did in 2013.
“My first time around, I would just say whatever came to my head, but this time around being in the diary room where you feel safe and you feel like it's just you and Big Brother, I was very aware that eventually, we would all get to watch this back,” she says.
“I watched my tongue. There were times when I was frustrated and I wanted to go the room and swear about Drew or Tim, but I just thought, ‘you know what? This is a game at the end of the day, and I wouldn't want them watching this back.’”
WATCH: Tully Smyth and Drew Anthony reunite in the Big Brother house
Though there are definitely things she likes from both the new (pre-taped) and old (live) formats, Tully is the first to admit she’d do away with housemates being allowed to talk about nominations.
“I still wish that we couldn't talk about nominations. That part's always been really hard for me,” she says.
“The scrambling is just, it's not fun. It's awkward. It creates tension in the house. You having to literally be on your knees, begging for people to save you. It's just a yucky feeling.”
She also missed the live evictions and being able to walk out of the house and into an auditorium full of fans, rather than the “sad” send-off she got this time.
“I was kind of sad just to grab my suitcase and hop in a car and drive away. That was a little bit anticlimactic.”
Big Brother airs Monday to Thursday on Channel 7 and 7plus
Looking for more Big Brother content? Check out the links below!
Confirmed! Here's the official cast for Big Brother Back To The Future
Tully, Drew and more Big Brother royalty return in first look at new season
Reggie Bird on life after Big Brother: "I spent all the money I had left on rent"
Big Brother's Trevor is back: ‘I’m out of my comfort zone’
What happened to Big Brother's Tully & Drew? A complete breakdown of their relationship
