Yes that is the way it always works, your antibody reaction (the swelling) does reduce as you get more and more stings, I don’t know anyone for whom this is not the case.
Your allergic reaction is a different matter should you become allergic then you will go into anaphylactic shock, this could happen at any time and we should all know the symptoms the most extreme being as I said above, but if you really wanted to explain what will happen then here goes;
Symptoms of anaphylaxis include:
• a red, raised, itchy skin rash (hives)
• swelling of certain body parts, particularly the face (angioedema)
• swelling in your throat and narrowing of your airways, which can cause breathing difficulties and wheezing
• nausea
• vomiting
• a sudden drop in blood pressure, which can make you feel faint and dizzy
• feeling like something terrible is going to happen
Obviously the skin rash is always likely to occur in a bee sting, to a greater or lesser extent, so look out for this with at least one of the others.
(In my case every time I go near my bees I feel something terrible is going to happen so I have to ignore that one as well!!)