Gay people tend to be more promiscuous then straight, gays will tell you that.
Homosexuals have a higher degree of STD/STI's then hetros.https://www.cdc.gov/msmhealth/STD.htm
HIV is obvious.
Anal cancer is higher.
The homosexual lifestyle is also more violent:http://www.bbc.com/news/magazine-29994648
Last year, the US Centers for Disease Control and Prevention released figures showing people in same-sex relationships experience levels of domestic violence just as often as those in heterosexual relationships.
But the conclusions of another study this year by the Northwestern University Feinberg School of Medicine in Chicago - a review of data from four earlier studies, involving 30,000 participants - go further.
"One of our startling findings was that rates of domestic violence among same-sex couples is pretty consistently higher than for opposite sex couples," says Richard Carroll, a psychologist and co-author of the report.
The Journal of the Family Research Institute using data from the U.S. Justice Department's Bureau of Justice Statistics and the Center for Disease Control concluded that "married men who are not separated are at least 25 times less apt to be domestically attacked than a homosexual male in an 'on-going relationship.' Even if we include all married and separated husbands, the risk of domestic violence in a male-male homosexual relationship is still at least 18 times greater."
Another study indicated that 83% of homosexuals report they have been emotionally abused by homosexual partners.
The U.S. Department of Veterans Affairs Domestic Abuse Fact Sheet states that "11% of women in homosexual relationships and 23% of men in homosexual relationships report being raped, physically assaulted, and/or stalked by an intimate partner".
A study published in The Journal of Family Violence reported among its participants that "Emotional abuse was reported by 83%" of its participants.
A study in the Journal of Interpersonal Violence examined conflict and violence in lesbian relationships. The researchers found that 90 percent of the lesbians surveyed had been recipients of one or more acts of verbal aggression from their intimate partners during the year prior to this study, with 31 percent reporting one or more incidents of physical abuse.
A 1985 study of 1109 lesbians by Gwat-Yong Lie and Sabrina Gentlewarrier reported that slightly more than half of the respondents indicated that they had been abused by a female partner.
Coleman, in a 1990 study of 90 lesbians reported that 46.6% had experienced repeated acts of violence.
A study of 113 lesbians reported (1994) that 41% said they had been abused in one or more relationships.
In their book, Men Who Beat the Men Who Love Them: Battered Gay Men and Domestic Violence (1991), Island and Letellier postulate that "the incidence of domestic violence among gay men is nearly double that in the heterosexual population."
The Journal of Social Service Research reported in 1991 that survey of 1,099 lesbians showed that slightly more than 50 percent of the lesbians reported that they had been abused by a female lover/partner, "the most frequently indicated forms of abuse were verbal/emotional/psychological abuse and combined physical-psychological abuse." 
A study of lesbian couples reported (2000) in the Handbook of Family Development and Intervention "indicates that 54 percent had experienced 10 or more abusive incidents, 74 percent had experienced six or more incidents, 60 percent reported a pattern to the abuse, and 71 percent said it grew worse over time."
Homosexuality seems to be more damaging and dangerous.