So my GF is on the pill and I'd be happy to rely solely on that but shes had a couple of close calls a long time ago with an ex and is a bit paranoid so we use condoms as well.

When we finish she always asks if its ok, meaning; check the condom isnt broken. I've never had a condom break so i dont know what its like; after sex the jonny is slippery obviously, from her, and so i spend ages trying to determine whether the slipperyness is her juice or mine.

SO my question: is it obvious when its broke, like totally torn apart and man juice dripping out or can it be a tiny imperceptible tear?

It'll be torn. Trust me on this, it's happened a couple times to me!

Where it's (usually) stretched over your wang, a small hole will turn into a tear because it's being stretched by the girth of your schlong.

Kinda like popping a baloon. The air pressure will make a pin prick bigger because the air is stretching it (also the air rushes out of the hole, stretching it further but whatever).

If you want to test it, what you could do is go to the bathroom, hold it over the sink, fill it with water and see if any seeps out.

The way a condom is made, a small tear will easily turn to a large, obvious hole quickly. Take a condom, make a small hole in it, then play with it a little (yeah, I just said that), and see what happens.

A condom is pretty strong, but once even a small hole is in it, it is weak as hell.