So:
I'm just going to be 100% honest w my opinions, and you tell me yours

Our ceremony will begin with live guitar music, with parents entering together before the 'real' procession. I always see parents enter together, often arm in arm. My mum and stepdad will not be a problem but:
Fiancee's mum and dad are divorced. Dad lives with the gf he cheated with (which would be absolutely fine if she wasn't just the most hateful woman I've met). Is it appropriate for Fiancee's Mum and Dad to enter together (they do have a friendly relationship) and dad just goes and sits with his gf??? Or is that confusing and awkward for those involved.......heeellllp! In my head, it makes sense that this is their son's wedding day, and can celebrate as parents, not a couple. Whew, LONG POST!
"The greatest thing you'll ever learn is just to love and be loved in return."
~Moulin Rouge