While I cannot be sure without actually looking at these lesions myself, I will say that they did not sound very much like a herpes infection. Still, I suggest that you schedule an appointment with your OB/GYN. The first clue is that a herpes infection is not in anyway associated with having a bowel movement. In addition, while herpes can be spread through sexual contact is not typically activated or exacerbated by having sex. In other words, the herpes flare or the lesions of herpes would appear independent of when you had sex and when you have a bowel movement. Herpes lesions are not typically described as small paper-cut like tears. They're usually described as small sores that burn and tingle in the area. People that have herpes infections tend to complain of fevers, generalized malaise, and a burning sensation in the groin just prior to the development of the skin lesions. Because your symptoms don't sound like this, I not surprised the doctor
who has actually examine these lesions believes that this is not herpes infection. With that said, I do think that you should be evaluated by somebody that is familiar with that area. Therefore I would suggest that you schedule an appointment with your OB/GYN for further evaluation of this problem. If the problem seems to be specific to the skin in that area, it might be that you would need a referral to a dermatologist
for further evaluation.