I Checked Out Of Curiosity

My son is in his teens i dropped him off at his grans to help her with some decorating i got back in the car i was about to drive off then i remembered i would be late going back for him i walked back to the house i was about to tap on the window to tell them, I saw something that surprised me normally when he meets her they hug and kiss, what i saw shocked, they were snogging with mouths open with there tongs in each others mouths i couldn't believe what i was seeing then his gran started to unzip his pants, i couldn't look any more she pulled his cock out and started to kneel down. what could i say i wanted to watch more because i couldn't believe what i was seeing it was not real