It is not discrimination to retain the millenia-old definition of marriage, which to my knowledge has never included "same sex marriage".
What will be discrimination, assuming the homosexuals get their way, is any restrictions other than age on who gets to be marriage partners. Multiple partners, human-animal partners (animals are property), inanimate object partners, including cadavers (property) - none of these can be "discriminated" against in light of this looney-tunes decision.
If the homosexuals are successful, and I lived in Mass, I'd immediately file suit for a multiple partner marriage. Next I'd file to include my sister - or brother. Then my dog. Then my car...
"My 'relationship' is as good as your 'marriage' and you have to acknowledge that under penalty of law ! Neener, neener, neener !"
Why stop at age? It's all relative. /sarcasm