I feel your pain.
MGD's older brother is a Canadian (yes, he gave up his citizenship) ethics and philosophy professor who specializes in health care and end of life (read "assisted suicide") issues. His wife just got her Phd in "womyns studies". Of course the sun shines out of their collective posteriors, or so my hubby's parents believe.
They heed every word he says, donate to Greenpeace, listen to NPR...I could go on. Needless to say there's a lot of tongue biting that goes on. And that is not in my nature, so once in a while I slip. Thus far, we've managed to be cordial...
Ouch. You know, we should start a support group?.. ;)
best.