Megan Fox Says She Craves Destructive Things, Posts Sexy Pics on 40th Bday

Megan Fox might be another year older ... but don't expect her to stop living on the edge anytime soon - because she says she's chasing anything that can hurt her.

The actress shared photos from a steamy photo shoot ... in which she wears a low-cut brown top and tiny black shorts.

Usually, Fox wears a winning smile, too ... but not in this case -- because her mouth is full with what appears to be a lit match.

She captioned the literal flaming hot snaps, "i desire the things which will destroy me in the end" ... adding a little context to the fire hazard.

Fox is clearly living on the edge as she turns 40 years old ... a milestone birthday she's celebrating without Machine Gun Kelly -- with whom she recently had a falling out.

Remember ... Kelly was trying to tell her how sexy she was after she posted some hot snaps online -- but she didn't want to hear it and ended up blocking him.