I'm not actually disagreeing that in some aspects homosexuals are more sexually open then heterosexuals (i'm not using the idiotic line of "sexually moral" which is just asinine).
That being said, the implications your continually making is this is due to the fact that they're gay, rather than numerous potential other factors.
For example, Catholic Priests in recent years have been apt to touch little boys...however that does not mean "Being a Catholic Priest naturally causes you to want to touch little boys", but could be that the situations that associate with being a priest (no marriage, vow of celibacy, position of power over the target) could be the actual cause. For example, in that theory you could potentially take a person that's an athiest, put him in a mentorish type position over a bunch of young boys, get him to vow from having sex or marrying with fear of major social and job backlash if it happens, and keep him generally separated from private time with females....there's a chance the same thing happens, and "Catholic priest" isn't in the equation at all.
Could it possibly be that our culture, for centuries, has made male promiscuity a thing that is looked at as a bonus. Is it not common in high schools, colleges, and bars of today to find men comparing their achievements of who they've "tagged" and making it a challenge to see if they can take a girl home for the night? Indeed, you could say there's a biological factor to the desire for openness and promiscuity in sex with men. As such, when not given the filter of the societal structure for females along with the more evolutionary traits of that sex, could it not be that the fact they're "homosexual" that is causing what you purport but actually simply because they're MALE.
In that case, Males are sexually immoral, which could be said, you would be proving that you yourself are sexually immoral mc.no.spin