You're making common mistake to conflate people's personal moral beliefs with the morality of interactions, with is universally dependent on whether consent has been given or withheld. It's not a matter of what I think, It's nature. When you violate somebody's non-consent, you violate their self-ownership and it leaves them feeling discontent. That is why rape is universally wrong, or, immoral. It doesn't matter you think rape is morally okay while you violate the non-consent of another, you are still, in actuality, infringing on somebody's self-ownership.
Nature says.
An action can not be objectively Immoral unless it violates somebody's non-consent, self-ownership, and or their property rights.
Consensus doesn't determine the morality of an action and or interaction; consent or withheld consent does.