id actually argue thats not really hypocritical. usually a guy breaking a lesbian couple up by stealing one of the girlfriends has huge sexuality correction vibes (since thats a specific fetish too), whereas a lesbian stealing another girl from a guy tends not to, and might even involve stuff about the stolen girl discovering a new part of herself. history of suppression of queerness and/or oppression of queer people reflects in art like that, so yeah, its not surprising to me that the dynamic that makes a queer relationship feels less icky or whatever than the one that destroys a queer relationship.
of course, it could always just be that people who prefer women, assuming you do, often just want to see lesbians fuck more than they do a man and woman lol, but it might not be, or it might be both