In a situation where you don't have any desire for foreplay, and your friend pushed you into it by using his power as a man to hold you and began the foreplay, even with all your pleas for him to stop but to no avail, but rather he releases you whenever he is satisfied, have you participated in the sin? Is it also a mortal sin on the part of the girl or lady involved?
Thanks. Looking forward to hearing from you.
What you are describing is rape, but I'm assuming intercourse did not actually take place.
To answer your question, let's look at a case in the Law of Moses where things went further and intercourse took place. It is found in Deuteronomy 22:23-29. In the times when the Bible was written, being engaged was considered nearly the same as being married. If the man raped the woman in an area where other people were nearby, but no one heard any protest or screams, it was assumed that the woman willingly had sex with the man since no one heard her cry out. In this case both the man and the woman were stoned to death. The woman because she violated faith with the man she was about to marry and the man for his participation in that deed. If the rape took place where it was unlikely anyone would have heard the woman scream, the man was stoned but the woman was presumed to be innocent of any sin. A woman has not committed a sin just because she was raped.
Therefore, in answer to your question, if you were forced against your will by a stronger man to be involved in lewd acts, then the responsibility is solely the man's. You did not do anything wrong.
However, it also means you have to be smarter about the situation. This man is not to be trusted in any way. You need to avoid him at all costs. You also need to let someone in authority know what happened to help protect you. Generally a guy like this will assume that if he gets away with one act, then he can do the same or go further.