Uh, you do realize that Freudian psychology has long been discredited? The only people who take him seriously are English and literary criticism majors. Even neo-Freudians have refined many of his ideas.
If homosexuality is partially genetic (which is almost certainly true), the question that emerges is due to what mechanism it is maintained stably across human populations. There is a good model of it, though the genes responsible for predisposing people to homosexuality are currently unknown.
Here is the study.
Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling ‘Darwinian paradox’. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness), accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait.
I guess this is slightly off-topic with regard to the psychology of homosexuality, but you referred to genetics, so I thought I'd clear things up.