I too have had this problem for a while. No disease, no yeast, always lube (glycerine
free, just because I find glycerine
stings, especially post-rip). I think my skin is just thin, I can essentially reach down and simply pull myself apart and have the same effect.
I only tear at the vaginal opening base and at the top of the anus opening. so, basically where thin skin stretches.
And, no, having sex every 2nd or 3rd day only, to allow healing up is not an acceptable option.