Pattie Mallette explained that she is happy about her 18-year-old son's relationship with the 20-year-old singer and actress.
"How can you not like her?" Mallette said of Gomez during an appearance on The Ellen DeGeneres Show. "She's so sweet and she's good for him, and they're great together. They're adorable."
Mallette was aged 18 when she fell pregnant with the 'Never Say Never' singer, and brought him up with the help of her parents after parting ways with Justin's father Jeremy Bieber.
The 37-year-old revealed that she made a vow aged 21 that she wouldn't be intimate with another man until she got married, and additionally promised her son that she wouldn't get a boyfriend until he was 18.
"I take that vow really seriously," she insisted. "I remember when I made it, I wrote it down on a piece of paper, I had someone witness it and it means a lot. I made it this far, I'm not stopping now.
"When I moved to Atlanta with Justin, because of all the chaos and how crazy it was, I told him I would focus on him and wait until he's 18 before I started dating. Now he's just turned 18."
Watch a clip of Pattie Mallette on The Ellen DeGeneres Show below: