We accidently set our date on the same day as our friends 1st wedding anniversary

Picking our date was a huge battle... my grooms parents were very set on us having a Sunday wedding (because they are vietnamese and it will be easier for his family and parents friends to come on a sunday) but obviously we wanted a big party so we settled on labor day of next year. Once we figured out the actual date that the wedding would fall on we realized that it would be the same day as one of our groomsmens wedding date and they were getting married this year on a saterday. So at this point we knew it would be the same day but we didn't consider it to be a bad thing... even joked at the crazy coincidence of it all- until they complained to us about it and asked us to change our date... I feel bad that they feel that way and I am afraid there will be tension between us all now ..but we have already signed our contract and don't want to disappoint his parents by trying to move it to a saterday. Is this really terrible of us? What should we do?