Certain sex scenes might be capable of getting audiences hot under the collar, but they can be incredibly awkward for the actors on set. Just ask Emily Blunt, who, while game to shoot it, didn’t find the experience to be anything other than cringeworthy. There were several reasons for that, not least of all the co-star she was cavorting with. Some stars refuse to film them at all, and while Blunt hasn’t necessarily been one of those actors, alth…