In a article that I recently read [Laura Gilmour, P. Melike Schalomon, & Veronica Smith.(2012). Sexuality in a community based sample of adults with autism spectrum disorder. Research in Autism Spectrum Disorders, 6, 313-318], they used multiple questionnaires. None were specific to ASD. Maybe you can have a look and see if those answer your needs. Also, regarding the parental perspective, you can check Holmes, L.G., Himle, M.B. et Strassberg, D.S. (2016). Parental sexuality related concerns for adolescents with autism spectrum disorders and average or above IQ. Research in Autism Spectrum Disorders, 21, 84-93. They used the Parent Sexuality Concerns Inventory. These articles are all in ASD research, but none of the questionnaires used are specific to ASD. Hope I helped!