Do mentally disabled people have sex? And do you think it’s wrong to have sex with a mentally disabled person?

Random thought but I’m autistic though on the lower side of the spectrum and I was thinking if I wasn’t..would I still get horny? And I mean ofc everyone gets horny but seriously what would I do with it? Would I even be able to understand it and consent to sex with someone else? It seems a bit wrong to me because they don’t fully understand what they’re consenting to.