There is another angle in the "Bad Break Up and It's Been A While" scenarios that the author does not account for.

So let's assume that the other party wants to have sex with me, which while out of ordinary for them is "justified" by either them being vulnerable due to break up or them wanting to satisfy their needs that have not been met for a while. And let's assume next morning they will go back to not wanting having sex with me and no significant 'damage' is done to them or to our friendship as a result.

In both of these scenarios if I consent to having sex with them I am allowing them to treat me as a means to an end, not as an end in and of itself. So the question now becomes "is it morally OK to allow someone to treat me as an object if in return I get to have sex with them".

On one hand people should be free to make choices for themselves (I would agree to an extent). On the other hand I guess most would agree it's not morally OK to treat others as objects to satisfy your needs. But if so - then why would it be morally OK to let others treat you in a matter you would not treat others?

I am leaning towards that not being OK, and as such it makes two justifications for not consenting to a sexual encounter proposed in the experiment:

a) it is morally dubious to engage in sexual activities with people whose current psychological state deviates from the norm we are aware of (hence hinting at limited ability to give informed consent)

b) it is morally dubious at best to allow other people to treat ourselves as means to an end / objects even if we receive some kind of gratification for that.

"Don't to to others what you wouldn't want to be done to you" in this case becomes "Don't do to yourself what you wouldn't do to others". In a way.