Imagine your date invites you over for a meal that a member of their family has taken long hours to excitedly prepare for you, but when they set it out in front of you one of two things happen, it smells horrid or you are allergic. Question is, what do you do?
Oh no! How awful. Well, if it merely smelled yucky, I would try some and make at least an attempt to be courteous about it. If it were something I'm allergic to, I would definitely speak right up and say so. My health is more important that not hurting someone's feelings.