My six year old dd1 (who was only bf to 5 months) will knead my breast while dd2 feeds. Ds who is 4 is not bothered. Think it is just natural curiosity, wanting familar comfort and maybe a little jealousy.
my 4 year old and my 5 year old will both try and get a grope of my boobs given half a chance if they see me undressed. There is nothing sinister about it. Theyre just babies themselves and i dont think either of them remember being breastfed either.
Dd1 is 3.3, and hasn't bf since 18 months. Dd2 os now 19 months and still bf. Dd1 will still occ sit on my lap next to dd2 and ask for the other side and try to latch on - so effectively lickimg my nipple. It feels a bit odd but is very occasional and fleeting, and I think she can see what a comfort it is to dd2 and wants to be part of that. I woul try not to worry, and see it as helping him with the transition to having a new sibling of ypu can
I'd say that sounds normal. Once when I was feeding newborn ds2 and had dropped of to sleep for a few seconds I awoke to see ds1 launching himself at my other nipple about to latch on. He was also 3 and a half at the time, but I hadn't breastfed him since he was 8 months old!
In the end I said he could have some of my milk if he wanted, but that as he was a big boy I would express some to go in a cup for him. He told me not to bother and that was it.
Really he was just missing being my 'baby' I found making a bit more of a fuss over the things he could do as a big boy (whilst reassuring him that he was my favourite eldest son - true!) really helped.
Sounds like curiosity and jealousy mixed. He remembers doing it and being loved. Now he's watching dd. He must miss it.
For us dd1 was off bf at 14mths but has become curious/jealous since dd2 a month a go. She's trying to sit on lap and cuddle up to spare boob and opened her mouth once. I just keep saying its for tiny babies not big beautiful girls. And hoping tv, books etc distract.
I think will wear off as becomes the new normal...