This is probably bait, but the homophobia of Lenin, Marx and others was a product of their time. In no way is communist theory intrinsically linked to discrimination of gays. The opposite is true since it stands for a fully equal society (not a "gay society", heterosexuals actually exist too). Socialism is supposed to ensure that all groups are equal in rights, meaning that in 2018, you can hardly call yourself a leftist/progressive while being reactionary about gay rights and marriage. Any possible argument for denying gays equal rights is based on reactionary and traditionalist bullcrap about "family values" that is incompatible with socialism. Don't divide the working class by privileging some of its members over others.