A goodbye hug

i am a divorced middle age male. a few weeks ago i had dinner with my first cousin and her busband. after dinner we visited for about an housr. it was getting late so i got ready to go home. my cousin told me she would walk me to my car. when we got to my car we hugged each other good bye. while hugging i felt an erection coming on. i felt sexual urges for my cousin... is this normal????