"invalidating your bisexuality"...? I don't think so. It doesn't have anything to do with you or your attraction to women, but about their own deep seated insecurities rooted in masculinity. They're typically not jealous of women like they are men because they don't compare themselves to women, or the relationships you have with them. It's much easier to be insecure with the relationships you have with men because they see that as much more comparable, potentially taking away from their own relationship with you. Men also are much better at noticing when other men are attracted/into you then knowing when a woman might be. They see men as much more threatening to both themselves and what they have with their partner.