Vaginal itching after sex that only happens on occasion is probably nothing to worry about. Not enough lubrication during.
Genital itching after sex can sometimes be due to dry skin or a lack of lubrication around the genital area. In cases where itching persists, this symptom could be a sign of an infection, allergic reaction, or sexually transmitted infection (STI). A latex allergy may be the cause.
But there could be a variety of reasons your vagina is itchy after sex. sulfates, alcohol, parabens, and dyes can also change your vaginal pH.