But if you look a bit wider, being gay really doesn't sums up the phrase 'M2M relationship'. There are thousands of intimate relationships between close friends, doesn't only pertain to sex.
If you go through the history of Alexander The Great, he had a love for his childhood friend, Hephaestion. Men live happily marrying a women... but if there exist a 'love for a man, somewhere in the past' how do woman react? It's not always gay/bi.