I went away for a few hours to make sure I responded appropriately: I seriously doubt you know what you are talking about.
Even those of us gay people who live in "gay ghettos" still function simultaneously inside the straight world. I'm not talking about being in the closet; I mean we have straight parents, children, friends, colleagues, etc.
To really be prejudiced against a group, you have to stand somewhat outside the members of that group. With almost no exceptions, gay people can't and don't have the "distance" to be prejudiced against heterosexuals.
Now, you may have heard the occasional joke about "breeders" or something similar. Those jokes are ironic and, frankly, defensive. We can discuss whether they are appropriate, but they do not reflect any true "prejudice" against our mothers, children, sisters, brothers, etc.
(ETA: To my everlasting sorrow, gay people are not exempt from the other prejudices of our day and time: racism, sexism, etc. We ought to know better and I cannot tell you how much it grieves me that all of us do not.)