It is not semantics to say such. When the words STOP and GET OFF ME (or some derivative therefor) are not used...and there is no act of trying to get him off (of the girl)...then those words can mean several things...1) I don't want to do this anymore or 2) Hurry up and finish I have to go. Considering the girl consented...any 17 year old boy would think the latter. To think otherwise is denying reality.
There are different ways to say things in which it will convey a certain message. If a person were crying while they said "I need to go home now" or if they were pushing a person away while they said "I need to go home NOW!".....I think any reasonable person would be able to distinguish the difference between that tone and a soft sensual "I need to go home now, baby", while stroking the other persons hair and inbetween oooh's and ahhh's, wouldn't you agree?
So you get a right to "finish" once you've started? Even when the woman either never was interested in the first place, or has been so completely turned off by you that she said "I have to go home now"?
Unbelievable.