No, this does not mean he had sex with another woman. You could have been infected with it before your husband. Are you saying that all three paps were indicating HPV or just the most recent one? If the most recent one was the only one that indicated it, then he probably passed it on to you and the cells are just now showing of the dysplasia (dont know if i spelled that right). Your body could rid of HPV all on its own. Some people have had it gone in 2 years, some more. If you did have HPV indicated in all three smears, then more than likley you had it before your husband.
I had all normal pap smears and I started dating my now ex boyfriend 9 months ago. I had a pap right before we started having sex without a condom, after we started having unprotected sex, about 5 months later--I had genital warts. So it took my body that long to show the signs of HPV. Some people may never get genital warts but my bodies immune system is already compromised so it couldn't fight the warts off.
But no, to answer your question.. it does not mean your husband cheated on you. It could be a possibity like everything else in life but seriously it does not mean he cheated on you, it just may taken your body a while to show abnormal cells.
Here is the website for the CDC for HPV:
(maybe it can help if I didnt