I'm currently reading through Michael Parenti's The Assassination of Julius Caesar: A People's History of Ancient Rome, and at one point (p. 114) he alludes to the incident as if it were a certainty. I am aware of the rumors that followed Caesar for the rest of his life about this, but most historians I read brush it off as famous slander and nothing more.
Do any historians of note really believe this? How likely is it to be true, and is there any evidence supporting it?
The historian Adrian Goldsworthy talks about this in his book Caesar: Life of a Colossus. Basically his and the opinion of most is that we have nothing to really go off besides records of the rumors, Caesar's character, and social norms at the times. From this we can say nothing of certainty but most attribute the accusation to just being slander but obviously don't rule out the chance that it happened.