Diddy Asked Cassie to Celebrate Christmas With Freak-Off in Text Shown to Jury

Diddy once had a sick, twisted Christmas gift idea for his then-girlfriend Cassie when they were dating ... a "freak-off."

The jury in Diddy's federal criminal trial was shown text messages in court Monday from January 2013, including one in which Diddy asked Cassie if she wanted to belatedly celebrate Christmas by having a freak-off ... which numerous witnesses in the case have described as essentially sex marathons in hotels with a hired male escort.

The conversation began with Diddy texting Cassie, "You horny" ... to which Cassie responded, "Lol yeah".

Diddy then texted Cassie, "Would you wanna celebrate Christmas and have a freak off tonight or Friday?"

Jurors were then shown texts between Cassie, alleged male escorts, and a man who apparently ran an escort service ... with Cassie setting up staggered arrival times at a hotel.