I thought some might find this study interesting …. from the School of Community Health at Portland State University, its a study titled Same Sex Marriage and the Perceived Assault on Opposite Sex Marriage

From the Study

"We found that state rates of opposite sex marriage in the U.S. from 1989–2009 do not significantly differ when same sex marriage and union laws are in force compared to when they are not in force, contrary both to concerns raised by opponents of same sex marriage and same sex civil unions."

The team found no changes to divorce rates or rates of opposite-sex marriagealso in the Nordic countries of Denmark, Norway, Sweden, Iceland and the Netherlands, after looking at similar studies done in after those countries allowed same-sex couples to marry.

They in fact note

"Same sex marriage laws could help reduce the number of homosexuals living closeted lives and entering into unhappy opposite sex marriages, such laws might both contribute to decreased numbers of new opposite sex marriages, but also reduce the number of opposite sex marriages likely to end in divorce because the marriage was undertaken to keep up heterosexual appearance by a homosexual participant."

The actual study is here

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0065730