I can't imagine that this is caused by long-term breastfeeding. My three
boys are all teenagers and all nursed past age two (one was almost five when
he weaned) and the main thing I notice is that they are just completely
oblivious to breastfeeding. We have LLL meetings here and many of my friends
are  breastfeeding,  and the boys wander in, admire and play with babies,
talk very comfortably to women while they are nursing, and barely seem to
notice. They just take it for granted. For the past couple of summers, our
LLL group has hosted a "Rock and Rest" area for mothers and babies at a
local festival, and when I'm on duty there one or more of my boys will
sometimes come in and visit me. Sometimes the mothers who are nursing babies
are uncomfortable - but the boys are always oblivious. Not embarrassed, not
staring or trying to sneak looks - just one more nursing mother when they've
seen hundreds. (And personally, I think it's great!)