Although they have been romantically linked, insiders say Selena Gomez and Austin Mahone are just good friends who "have a lot of fun together".Selena, 20, has been linked to the 17-year-old singer following her split from Justin Bieber but sources close to them insist the duo are simply close pals.A source told E! News: "They're really good friends and have a lot of fun together."Selena recently ended her on/off relationship with Justin once and for all after he was spotted hanging out with Miley Cyrus, even though she is engaged to Liam Hemsworth.An insider said: "It was already over with Justin, but seeing him hang out with Miley was the last straw for Selena."She's not a Miley fan by any means and feels like Justin purposely did it just to p**s her off. She's completely severing ties with him now."The 'Spring Breakers' actress' family and friends had reportedly warned her to stay away from Justin, 19.A friend explained: "She's finally taken some of their advice to heart and swears it's finally over with him, for good."She doesn't see herself getting back together with him and just needs to move on."View more photos of Selena Gomez and her ex-boyfriend Justin Bieber in the gallery below.