Reese Witherspoon is called a prude! She gets red faced due to "funny" love scene with Vince Vaughn.

Hmmmmm. Reese is a prude? Maybe that's why she and Jake are getting along so well............
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It's been widely reported that Reese Witherspoon and Vince Vaughn can't stop butting heads on the set of Four Christmases but apparently it was a scene where they're supposed to bump uglies that really has Reese hot and bothered — but for all the wrong reasons. "Reese has an issue with the scripted love scene," an on-set source tells PageSix.com. The sex scene is written as a funny, American Pie-style romp, but "Reese is such a prude, she thinks it's just too much," the insider adds.
While Reese may be the bigger star of the two, Vince definitely has more clout on set. Not only is he one of the film's producers but he also oversaw most of the writing, so the sex scene will most likely be filmed as written. But Reese may not be the only one scoffing at some of the film's content — there is a chance Vince's ex-girlfriend Jennifer Aniston won't be too happy, either, because Vince's character is oddly named "Brad." Honestly, to play a character named after your ex-girlfriend's ex-husband — it's all so meta! Only in Hollywood.