You can't stop it. It is ingrained. And I would contend that the best way to limit promiscuous sexual behavior is to allow permanent unions of homosexuals. I fail to see how this in a any way affects heterosexual marriage, but denying this right does seem to encourage the very behavior you claim to worry about.
I don't understand. Has someone outlawed "permanent unions of homosexuals"? Who is stopping them?
And I would contend that the best way to limit promiscuous sexual behavior amongst homosexuals is to encourage them to leave that lifestyle. Promiscuity is part and parcel of the lifestyle.
Just because a union is called permanent doesn't mean it will be.
People will be unfaithful regardless of how permanent a union is professed to be.
Look at the heterosexual women and men who serially commit adultery and pathologically lie about it.
And those who screw around, until caught, while professing to be 100% faithful.
That won't work either, gay marraige is a bad idea and caving into their temper tantrums won't change anything either.
"but denying this right does seem to encourage the very behavior you claim to worry about."
Men do not have the right to marry men.
That is not a right, and never has been.
Marraige is termed and defined, as it has been for thousands of years, as being a union between a man and a WOMAN.