I note Mr (MP)'s talking about 'genuine commitment to marriage equality'.
Of course, given the biological basis for marriage, I'm all for equality as well. What does puzzle me is how the current debate pretends that there is no functional issue here, but one of mere 'being in love'.
Marriage has in view procreation. Eons of evolution have shaped this, no law, no culture, such that reproduction requires a zygote and no pair of the same sex can make one.
Thus the current debate is about marriage debasement, commoditisation of children and the intrusion of the law into the fairytale world of happily ever after romance.