Is the universe flat?

And more generally what do you think about Einsteins theory of curved space?

one the one hand curved space might explain bendy light? Because I read it's impossible for light to go in a perfect straight line because the universe is curved (they say).

Lol they are obviously too busy trying to figure out how the earth can be flat before they even try to fathom the rest of the universe 

fun fact the universe is flat

space only curves around massive objects 

fun fact the universe is flat

space only curves around massive objects 

this.
OP must be confused, because when they say the universe is flat, they mean it is neither open (hyperbolic) or closed (spherical)
the curvature of space-time doesn't have to do with the visible geometry of space itself, but rather the curved tensor field around massive objects. don't you love it when noobs come in with one ill understood scientific idea and use it in FE arguments?

one the one hand curved space might explain bendy light?

No, it wouldn't.