The publication has pictures and video of Tristan appearing to kiss a mystery brunette in a New York City club on Saturday, April 7.
It was back in September that Khloé revealed she was expecting her first child with Tristan.
“My greatest dream realised!” Kardashian captioned an Instagram photo of Tristan holding her bare baby bump at the time.
“Tristan, thank you for loving me the way you do! Thank you for treating me like a Queen. Thank you for making me feel beautiful at all stages! Tristan, most of all, Thank you for making me a MOMMY!!!! You have made this experience even more magical than I could have envisioned! I will never forget how wonderful you’ve been to me during this time. Thank you for making me so happy my love!” she continued.
Khloé is yet to respond to the explosive video. Check it out here.