Something Hiding In A Holiday Home Attic/Loft?

Ok, so I saw this film where two or three couples, as well as some single people, are in a coach going to a holiday home to try and rekindle their love. There's one, maybe two, married couples, and a young girl and her boyfriend, as well as a single lesbian. I'm not sure how far into the film people start dying, but I know the married man goes up into the attic or loft, and maybe gets his head bitten off. He's up there talking before he's killed, and blood sprays down onto the people waiting below. His wife starts screaming. Then this thing comes down and starts killing people.

The young girl's boyfriend dies, and after the lesbian seduces her at night, I think it's night anyway, but maybe not, because I think they may have been sleeping in the same room in sleeping bags. Anyway, the young girl, after being seduced, starts to believe her boyfriend is still alive and begins carrying his head around with her. I'm not sure if they all die in the end, but the young girl does, because the lesbian is screaming her name as the beast drags her away.

Any help would be appreciated. Thanks. (It wouldn't let me post it all in one go.)