Justin Bieber Leaves Valentine's Day Visit 'Really Inspired'

Meeting 'Mrs. Bieber,' a 6-year-old fan battling cancer, 'one of the best things I have ever done,' teen superstar tweets.

Justin Bieber spent the day before Valentine's Day with a special girl. No, he wasn't with his lady love, Selena Gomez — instead he visited Monday with a 6-year-old Belieber, Avalanna Routh, who is suffering from an aggressive form of cancer.

In a photo posted to his Twitter account, Bieber is seen hanging out with the young fan, dubbed "Mrs. Bieber." And the experience seems to have really affected him. "Hangin out with a special little girl. #MrsBieber," he tweeted about the meeting. "That was one of the best things i have ever done. She was AWESOME! Feeling really inspired now! #MrsBieber."

Avalanna's dream came true after her family started a Facebook campaign for her to meet Bieber, which, along with her pretend marriage to the teen superstar, was reported by a Boston-area news outlet. When the always-charitable Bieber caught wind of the marriage and her family's efforts, the "Today" show reports, he flew Avalanna and her family to New York. The 6-year-old, whose "marriage" to Bieber was orchestrated by the charity the Jimmy Fund, has had an incredibly rare form of cancer called AT/RT since she was a baby.

"Got some really great ideas from today. ways to #giveback. #MrsBieber really inspired me. Really," he said, adding, "BEST PART OF MY DAY."

Bieber is involved with several charities through his Believe charity drive, including Pencils of Promise, the organization started by Adam Braun, brother of his manager Scooter, that builds schools for children around the world.

The pop star also made headlines recently when he tweeted about a fan who needed an organ donation, skyrocketing registrations at the Trillium Gift of Life Network donor bank in Ontario, Canada.