Um I most certainly did not.PS - I did not sleep with everyone I dated; neither did my husband. Apparently we are in the minority in that respect.
However, this question references an "ex." To me, that implies an ex-boyfriend.
I would consider somebody an actual "boyfriend" if I had a long-term, exclusive, relationship with them. And if I was in love with them. So yes, in these scenarios, sex was involved.
I certainly don't consider all the many randos I dated for a month or 2 an "ex." Do most people?