The blonde star was mortified when her parents insisted on watching Jennifer’s Body, in which Amanda and Megan share a steamy encounter.
She said: My mom and dad have just seen a film of mine with nudity. My mom saw me have sex with two different types of people on screen. She knows it’s acting but it’s not necessarily OK with me.
It was difficult when my mom sat down with me to watch Jennifer’s Body.
Amanda previously revealed she found locking lips with 23-year-old Megan for the high school horror movie uncomfortable.
She said: "It was my first time doing a real kissing scene with a woman. It is just weird. It is a woman.
With a woman's smell - soft and floral-y - and maybe the pheromones are different. Something about it felt uncomfortable for me."
Amanda - who is dating her 'Mamma Mia!' co-star Dominic Cooper - also had to canoodle with an older Hollywood actress in forthcoming film Chloe.
The 23-year-old star has admitted the same-sex scenes were a challenge.
She explained: "I have a love scene with Julianne Moore in 'Chloe'. When you are done with the scene, you just think, 'Oh God, I can do anything. I have just had sex with a woman!' "
