Footage also shows him hooking up with two women at a hookah lounge in Washington, D.C., six months ago - while Khloe was three months pregnant. Tristan is a man Khloé built a life with and saw as her forever. A source previously told PEOPLE she planned on giving birth there, and her famous family would fly in.
Thompson is seen in another TMZ video, meanwhile, entering a Manhattan hotel while accompanied by a woman that same night.
The family "is pretty much set on heading to Cleveland so that they can be there for her when the s- hits the fan", an insider said and they are "livid" with Thompson. She filed for divorce in 2013, and it was finalized in 2016 after being briefly called off due to Odom's near-death experience from overdosing at a brothel.
"Lamar feels awful for Khloe", a source told the magazine.
Khloe has been in constant contact with her friends and family throughout.
Tristan Thompson is supposed to be playing a basketball game at home tonight - the last home game of the regular season for the Cavs, however, in light of the latest developments, that could be iffy. She's also talking to their lawyers about Khloe filing for sole custody of the child.
The number one issue in the foreign media today - the betrayal of Tristan Thompson to his pregnant sweetheart Chloe Kardashian.
"Khloé could probably convince herself to get over the fact that he maybe, kind of, sort of, hooked up with some groupie while out on the road", they added.
"How could he do this, and so publicly, when their baby daughter could arrive within a week?" the source asked.
"The [alleged cheating] video hasn't stopped the Kardashians from making sure her day will be one of love and respect", the source said.