The 'Alejandro' singer separated from barman Luc Carl a number of years ago but she has decided to give their relationship another chance.
A source told People magazine: "Gaga's first album is entirely about their relationship and her song, 'You and I', is about how they got back together. They've been in love for a while."
Gaga and Luc were spotted at a New York Mets baseball game together last month, their first public date since getting back together.
In the lyrics to 'You and I', the 24-year-old pop star sings: "It's been a long time but I'm back in town/But this time I'm not leaving without you. You taste like whiskey when you kiss me oooh, I'll give up anything again to be your baby doll, Yeah this time I'm not leaving without you."
Gaga is believed to have separated from her last boyfriend, stylist and friend Matthew Williams, in June.