It sounds like you got off pretty easy with just some embarrassment, OP. I've never been caught, but I have admitted to it to my SO and he was deeply hurt like I had cheated on him or something; can't imagine what'd happen if caught in the act.
As long as you're just unzipped or correctly have just the front pulled down you can easily recover with good reflexes and listening to your surroundings carefully
Can't fuck a girl on her period... can't jack off with someone else in the house... OP, you sound a little high strung tbh. Hope it all works out for you.
We're talking "I once went down on a girl only to realize what was up when my mouth tasted like pennies" and I've been put off by the whole thing ever since. On the surface I KNOW it's not a big deal but it instantly kills my boner if I see blood.
That's unfortunate. With my lady, sure we both want to make sure the other one is taken care of under normal circumstances but when she's off limits she's still totally willing to help out. She still finds it fun.
But hey at least it's no big deal that your girlfriend caught you. Some ladies get weird about that so I'm glad this is just a funny story and not a horror story.