Is it normal to wank it?

when I was a teen on vacation with the family. Decided to do my own thing and check out girls around the resort. Walking up to the pool area I noticed a woman was lying face down on her pool chair and her bikini bottom was too loose and her vagina was exposed. I kept walking back and forth to build up memory for later jerking. When I felt I was good to go I went to turn and go back to my room but then I saw my dad walk over to the woman and sit down next to her. It was my mom.