Condom Blues

so everyone says condoms are like 95% effective (forgive me if I'm wrong about the statistic) and that they will almost NEVER break, right? well, unfortunately for us, my partners breaks nearly every time we use one. And I don't understand why. I watch carefully to make sure he puts it on correctly, and we've tried different brands and sizes but alas! Still breaking! I don't know what to do! It's awfully rediculous. Has anyone else had this happen, and if so, can you offer a solution?