Yes, I would have been bothered by seeing that kind of movie with my parents at your age--not that such movies were available in regular stores or Red Boxes then.
I guess on some level all of us have trouble imagining our parents in sexual activity! My mother (at 84) wouldn't know what to make of such movies. She seemed to even be bothered when there were long kissing scenes in shows when my sis and I would be watching them with her when we were younger.