Marrying gay couples in a church would make a complete and utter nonsense of the church itself, you just couldn't take them seriously anymore if they allowed it.
Er - bullshit? And rather a different argument from the ostensible "it's fine but they shouldn't be forced to" line of this thread 
Methinks some true colours are oozing out now, and it ain't pink.
(ps I'm a Christian, although not these days a churchgoing one, and I absolutely think gay people should be married in church if they want to.)
(pps I am also a single mother, which I guess makes me pretty abhorrent as I have deprived my youngest child of having a parent of each sex in his life. Burn me at the stake if you think you're 'ard enough.)