You have several hurdles you would have to overcome in order to prevail against a motion for summary judgment in a civil action for the tort of assault or battery.
1) you have to prove that she knows she had a sexually transmitted disease at the time of the sexual intercourse. This is not as easy as I may sound. You will not be able to rely upon "everyone knows this" evidence. You would have to produce diagnostic evidence showing she has knowledge.
2) you have a problem with damages. Every tort has to be proved with damages. While assault can be established without some physical injury (being apprehensive of an immediate offensive or harmful touching), fearing an infection from a transmitted disease will be difficult to use. Especially since your boyfriend was not aware of her alleged condition at the time of intercourse. Damages for Battery would be easier to establish, but again, without a transmission of the disease, his is problematic.
Contact a local personal injury lawyer for more information. Good luck.
My colleague's analysis is good but you have no chance against the other young woman. If anyone would have given you herpes it is your boyfriend. In any event, no damages no suit even if you found a legal theory that works.
Solve this and similar endless future problems by picking better men. Truth: when a man cheats on you it is not the moral or legal responsibility of the other woman.
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