I don’t even understand how this works. Is the guy on the other side of the hole also on the other side of a thick shower curtain? Does he end up with several inches of vinyl (in addition to what he was expecting) in his mouth??? Wouldn’t a condom at least be more comfortable in his mouth? Maybe I am glad to not understand how this all works.
You cut a hole in shower curtain, and insert tab A into her slot B with the shower curtain between the two of you so you don’t pant and breathe all over each other while exercising your government sponsored right to fornicate. Think of it as a full body “mask” to prevent you from contaminating each other (assuming a condom is involved.