"B" is easier to make. "P" need air to be agressively expulsed at the same time. So B is kind of swallowed and P is spitted, if you will. Keep in mind that they are very different for us, if you try mumbling something in between will upset us. When you'll get used to it, once yu tune you ears, you will get it. I can relate to you because French don't hear English "H" and it too me a lot of time (years) and effort to get it, but now I can see how silly I was trying to avoid them.