Anyone can change their mind about anything at any time. Probably except a pregnant woman giving birth. LOL.
Really, stop means stop and no means no. Sure a guy may be aroused and ready to go at it to finish into a climatic explosion. But, even still, stop means stop.
If I love a salmon dinner and one is right in front of me while I am enjoying it, but I decide I have had enough and want to stop eating......what are you going to do, shove it down my throat? Of course not. I am done, I want to stop, no more...all mean the same thing: cease the activity and do not proceed.
We all know what a stop sign means. It means you have to stop, as in, all four wheels must cease to roll. If you go to a rolling stop and get a ticket for failing to stop, are you really going to argue what the word STOP actually means with that police officer who just wrote you a ticket? Stop means STOP, all day long.