Sex during outbreak

I'm wondering what the risk is of spreading HSV 2 if you are having an outbreak. I have been seeing someone for a few months now and he knows my status. He sometimes chooses not to wear a condom. I found a small bump the other night on my butt after we had sex without a condom. I always check before I have sex and I'm worried I missed this and had it during sex. It's super tiny and not open or anything, but I'm pretty sure it's still from H. I take a daily suppressive and lysine. What are the chances of it being spread given that I missed the bump beforehand?

I've read 75% chance transmission outbreak.

Ok, thank you! I'm hoping it just came up after or isn't related to H. Fingers crossed.