How Gay Marriage Strengthens Straight Marriage (?!)

I have never once bought into this idea that legalising same-sex marriage will weaken heterosexual marriage. I have always maintained that the one will have no effect on the other. Apparently though, there is an impact, just not the one that opponents of it have envisioned. According to this post by Andrew Sullivan, straight marriage benefits from gay marriage. One of his readers writes:

"Why aren't you married?/When are you getting married?/You should get married" became a socially acceptable comment even in the most liberal of circles, and those opinions started getting air time. At my former employer the first year of gay marriage, I felt like we had some sort of wedding shower every other week - the gay couples got married and then all the straight ones started planning weddings too.

Interesting... It will be something to watch statistics on marriage as well as on divorce in the next decade or so in jurisdictions that allow same-sex marriage. Many opponents of gay marriage would like nothing more than the strengthening of the "traditional" family (which is not all that traditional, but that's another post). What if gay marriage, over the long term actually strengthens straight marriage? Will Jerry Falwell's head explode?