HPV is passed along by skin to skin contact. The HPV most of us are talking about is the strains which can affect the genitals (vulva, vagin, cervix, penis, anus, rectum, mouth/throat). So if any of those sources of skin touch others of those sources of skin, then it is possible to be exposed to HPV.
All it takes is one person to have been exposed to HPV, to pass it along to the next.
Unless both of you have never been with anyone (in any sort of sexual way - not just intercourse) then it is possible to be exposed to HPV.