Yes, Autistics have sex, can have sex, and can want to have sex.
Some Autistics actually get married and have children through biological means, otherwise known as having sex. Some Autistics are gay, lesbian, bisexual, transgender, genderqueer, or pansexual, and they have sex too.
(Yes, some Autistics don't have sex or haven't had sex or don't want to have sex, but the reasons for that are as varied and diverse as for non-Autistics who don't have sex or haven't had sex or don't want to have sex.)
Being Autistic does not mean lacking the ability to have sex.
And no, asking Autistics if they've ever had sex or can have sex is not okay. It'd be inappropriate and rude to ask a non-Autistic, seemingly "normal" person if he, she, or xe has ever had sex or can have sex, and it's equally inappropriate and rude -- not to mention incredibly offensive and insulting -- to ask an Autistic if he, she, or xe has ever had sex or can have sex.
And for the sake of everything green on the earth, please stop Googling "can autistics have sex." Please.
An annoyed Autistic blogger