Imagine a pregnant woman who can become nauseous just smelling certain foods. You've all heard about that (and many of you gave experienced it). That's what it can be like for people with severe nut allergies. Mr BlueSky has them and I've had to make a lot of adjustments in how I handle food. However, while Mr BlueSky will refuse the nuts, he would not expect a seat mate to refrain from enjoying them, even if it makes him somewhat uncomfortable. If this FA has a severe smell reaction, she should have (a) politely asked OP if he'd be willing to refrain due to her allergy, (b) been prepared to accept his "no" if necessary, and (c) either ask to move (if very severe) or put up with it (if less severe). There's a point at which allergy sufferers have a level of personal responsibility for not exposing themselves to known trigger situations.