that is definitely not hsv-2, genital herpes. the description sounds nothing like it.
go get yourself checked out though. It might be a bacterial infection.
As it is followed by sexual activity and friction down there, it is most likely nothing more than 'folliculitis' which is no big deal. :) it's a minor bacterial infection which results from sexual friction.
you shoudl go to a doc or clinic and tell them your story, and see what they say. most likely they will give you some Antibiotics which will kill it.
but be careful in the future and teach those girlfriends to use more saliva! ;)