I recently learned this the hard way. I did not know of culture traditions that happen at a wedding and I did what I would normallly do. After an apology and forgivenss from the grandmothers all was right.
I have since started asking this question when I do a consult of the ceremony. I will then read up on what is expected of me. Learning is always an ongoing part of life and for me learning a new culture is part of it.
Something to live by for all. Keep an open mind about cultures and faiths you may just learn something about yourself and be a better person because of it. Respect that part of the couple you are marrying for it is their day not yours. Embrace life you only get one.
Blessings on everyone and have a great, adventurous, fun filled day.