Yup, It can be used by couples too who are in LDR or who want to explore their sexual kinks without involvement of any other person.

But in terms of sexual stuff, I imagine it will mostly be used for casual sex with non-sentient AIs by individuals. This will eradicate the involuntary dependency of humans on other humans for sex. With this, sex for fun will be much better than casual sex with other humans.

Imagine organising a huge sex party with non-sentient AIs on a spaceship near a strange planet and doing whatever the hell you want to with them, or living out your extremely taboo fantasies which you do not wanna disclose to other people. After this, sex with other humans will be an option and not a necessity.