this isn't really slutty, more just naive and trusting on my wife's part probably, but she had a friend in high school who basically groomed her to the point where they would masturbate together. First started with the friend being very casual with nudity and always talking about masturbating and porn. Wife slowly got comfortable with it too and one day the friend was talking about masturbating techniques and just start demonstrating them, first over her boxer shorts she was wearing but she took she off she she "could show her better". Wife just watched that first time but the next time the friend urged her to try it and she did. Wife just figured this is what best friends. They started doing this frequently, sometimes watching porn but more often just watching each other. This went on til friend moved across town. Wife got a new best friend and asked her about how she masturbated and friend was weirded out and that's when she realized that was not a normal thing to do haha