Kardashian-Jenners blank Rob and Blac Chyna engagement

The Kardashian-Jenner clan have blanked news of Rob Kardashian and Blac Chyna's engagement on social media.

Sisters Kim, Khloe, Kourtney, Kylie and Kendall - all active users of apps Twitter, Snapchat and Instagram - have maintained a social media blackout amid news their once estranged brother is officially engaged to the glamour model.

His family have flown to Vail, Colorado for a well-timed snow-sports break, which is being filmed for show Keeping Up With The Kardashians, and are not speaking to the media. However a source says Rob has been in contact family matriarch Kris Jenner since the proposal.

"No one (in his family) is jumping up and down with excitement today," a source tells People.com. "They have made a united decision as a family to not comment on social media yet about Rob's engagement. The news is not shocking, and not totally unexpected," the source added.

Rob, 29, and Blac, 27, who is the ex-partner of Rob's sister Kylie's boyfriend Tyga, celebrated their engagement at a strip club in Las Vegas.

The couple looked happy as she showed off her gorgeous seven carat custom made round brilliant cut diamond in an eternity band setting, made by Rob's longtime friend, jeweller Ben Baller.

Rob apparently covered a room in Blac's house where he proposed, with hundreds of rose petals. He also adorned the place with candles before dropping to bended knee in front of Blac and her mother, reports TMZ.

However, sources close to the family fear that Rob is being manipulated by his girlfriend.

"There has been a fear that Blac Chyna is manipulating the situation with Rob. That he is getting himself into a situation that is not ideal for him. Let's just be honest, no one is really hoping for a marriage to happen," added the source.

If the couple do marry, Blac, plans to go by her real name, Angela, and will take Rob's name.

"She's soon to be Angela Kardashian. She's ecstatic," the rep told People.com on Tuesday (05Apr16).

The couple are rumoured to be considering filming a reality show focusing on their engagement and wedding planning.