The Keeping Up With The Kardashians star, who's expecting her first child with the basketball player, recently praised the athlete on her app.
'I'm so blessed that Tristan has been beyond supportive! He's helped me overcome any fear or anxiety that I have,' she wrote. 'He's always so reassuring and confident about everything when it comes to our baby.'
But, In Touch alleges that Khloe's praises of her 6-foot-9 beau are a front to the turmoil the couple are facing behind closed doors.
The publication's multiple sources revealed that Khloe's boyfriend of a year and a half has been 'flirting up a storm' with other women, and remains in close contact with ex-girlfriend and the mother of his first son, Jordan Craig. In Touch further reports that the Tristan refuses to give up his 'bachelor pad' and refuses to marry Khloe.
Sources told the publication they fear Khloe is reliving her past, comparing Tristan to the Good American moguls' ex-husband, Lamar Odom.
'Khloe seems to be doing it all over again,' a Kardashian insider told In Touch. 'She has chosen another basketball player who has cheated in the past and could seriously break her heart.'
The Kardashian family are particularly concerned over the basketball player's close relationship with his ex-girlfriend, 26-year-old model Jordan, who was pregnant with Tristan's first child - 15-month-old Prince Oliver - when he and Khloe began dating.
In Touch reveals that friends close to the Kardashian star warned: 'If Tristan cheats on his pregnant girlfriend with you, he will cheat on you with another woman.'
An insider also revealed to the publication, 'Khloe doesn't listen to her family when it comes to love. She can't seem to pick the right man.'
In Touch claims that Khloe is ignoring her family's advice and working to win back her beau. Khloe and Tristan have yet to respond to In Touch's claims.