Can I get genital warts this way? Please help!

I know that regular warts and genital warts are two different things, however I have heard that regular warts can turn into genital warts. So here's my situation... My friend has a huge wart on his arm. He doesn't have warts anywhere else to what I seen. He wants to go down on me but I am not sure if I should let him. If his tongue/saliva touches my vagina will I get warts on my genitals due to the fact that his saliva is touching my genitals? Or does he have to have warts on the tongue/mouth for me to get it on my genitals? Like I said he only has one on his arm.