Justin Bieber's fling with Kourtney Kardashian is an "ego boost" for him.
The 21-year-old singer has reportedly been hooking up with the 36-year-old mother-of-three and is thrilled that she is interested in him.
Woman's Day revealed that the stars were seen together a few weeks ago at Nice Guy, a restaurant in LA, before sneaking away to Bieber's Montage Beverly Hills hotel room, where Kardashian was spotted leaving around 4am.
A source told the gossip magazine: "She's calling it a fling, but her feelings are clearly stronger than she's letting on.
"She's constantly texting and wanting to see him. She's been secretly smitten with him for months."