Just caught the tail end of this post, so perhaps I'm way off topic and if so, I apologize. Everybody is happier with thinner condoms, but please make sure you NEVER use Lambskin condoms. These condoms are made from animal membranes that contain tiny holes. These natural holes are too small for SPERM to pass through, so they are excellent if preventing pregnancy is your only concern. They should NEVER be used to prevent the transmission of HIV or STD's as these viruses are much smaller than sperm and easily pass through the holes. I shall butt out now.
Any break with any condom is noticeable because it is down the seam and the condom is in tatters. Oral is not a risk so that part of your episode is irrelevant. No condom can protect against all std so you should visit the std forum for more info.