Rob Kardashian posted a cryptic tweet on Tuesday while the rest of his famous family enjoys their vacation in Thailand. The only male of the Kardashian family has noted his struggle with depression and weight loss in previous episodes of his family’s E! reality show Keeping Up with the Kardashians.

Kardashian tweeted to his nearly 5 million followers, “no one will ever understand how much it hurts.”

According to Us Weekly, it isn’t known exactly what he’s referring to but his ex-girlfriend, Rita Ora, did give an interview just before the tweet was posted gushing about her boyfriend Calvin Harris.

On his Instagram page, he deleted every picture except for one – which reads "April Fools prank: replace all the sugar in your house with cocaine.”

Meanwhile, his sisters; Kim, Khloe, Kendall and Kylie, his mom Kris Jenner, Bruce Jenner and step-brothers Brandon (and his wife Leah) and Brody Jenner have been posting to their social media pages showing how much fun their vacation has been. Kourtney and Kardashian and Scott Disick were not on the trip.

Kim posted a picture with Brody, writing, “Bro Sis bonding.”

image via Instagram from Kim Kardashian

Khloe also posted a photo of herself walking on the beach with Kendall, writing, “Forever my always. Forever my sister. Forever my smile.”

image via Instagram from Khloe Kardashian