Genital warts (condyloma) are caused by the Human papiloma virus, or HPV. HPV is sexually transmitted but does not require penetration in order to transmit from one partner to another. Close contact from skin to skin is enough to spread the virus between partners. The incubation period required before genital warts appear is from six weeks to three months, although the virus may remain dormant into your cells before it grows into a wart.

One possibility for the recent contraction of the warts might be possible infidelity on your girlfriend's part. You may need to sit down with her and discuss the situation to learn more.