As if "Platonic love" is non-sexual! This is just later Christian scripts, designed to eliminate sexually divergent evidence.
The tension I'm wanting to point out is the cultural programming (be straight, get married) at variance with the moment-by-moment shifts in feeling. Like in the line I quoted: "Sam felt that he could sit like that in endless happiness forever, but it was not allowed.”
A plausible reading for a literary critic might have the spider penetration—and then the cripping orc rape—happening as a manifestation of Sam's growing sense of connection to Frodo. I don't read it as a history but as a dream!