Do something about it, step outside your comfort zone. If bisexual activism for you means the creation of bi-only space be careful that 'community' does not become segregation, isolation and the legitimation of oppression. Enjoy your opportunities to love hets and homos. Don't say 'lesbian and gay men' when you mean 'Queer'. We'd like it to include us so please don't use it exclusively.
Bisexuals are everywhere.
If a friend, whether they identify as bisexual or homosexual, starts sleeping with someone of the opposite sex, don't ignore them, lecture them, persecute them. Desire is unpredictable and excellent. Consider what it gains you now, and what it might gain you to give it up.