Treatment for HPV and warts is not a CURE for HPV and warts.
In other words, there is not presently a cure, so treating existing warts does NOT mean new warts will not appear.
That warts appeared again may or may not be related to sex at all. It may be a coincidence. It may be your partner -- especially if you were not practicing safer sex, which you WAY should be, having HPV -- had a strain of HPV you have just contracted and did not have before.
But yes, you need treatment when warts appear, and having HPV, it is likely you will get them on and off through your life. You can help to prevent that simply by taking care of yourself and your body and practcing safer sex.
Editor and Founder, Scarleteen
My epitaph should read: "She worked herself into this ground."
-- Kay Bailey Hutchinson