While the birthing scene in The Twilight Saga: Breaking Dawn Part One had us on the edge of our seats, it had the cast in complete stitches.

In these just-released bloopers from the vampire flick, we see Robert Pattinson cracking up after sucking blood from Kristen Stewart's arm. As you do!

The clip also features Taylor Lautner admitting that it was hard to keep a straight face at times, revealing: "There was one point where Kristen stops breathing … and all of a sudden I [have to] wrap my whole mouth around her lips and give her CPR. It ended up working but it was funny at [times]."

Is it just us or did it suddenly get really hot in here?

Click through to watch the clip!