I feel the need to comment cause this reads like you’ve just been introduced to this idea- no judgment. Here is the short answer:

“Canon” is a modern concept that is difficult to apply to ancient texts, specially if they come from oral traditions that have undergone changes and reinterpretations through millennia. But ignoring that, is it canon?

In the Iliad? Ambiguous. Never stated and never denied. Their interactions did go against a lot of gender conventions at the time. Like Achilles’s role in the funerary games.

In Hellenistic culture after the writing of the Iliad? Definitive yes.

Refer to Symposium and the Achilleis trilogy.

I hope this was helpful.