I'm glad I came across this thread, because I feel the same way about it becoming irritating and almost unbearable. I haven't ever let her twiddle with my other breast so I don't know how you all have been able to deal with that so long!! I didn't even like for her to play with my hair and would pull it back so she couldn't touch it. She now just twirls her own hair when she's sleepy.
I have tons of milk somehow... I lost almost all of it at 8 weeks and DD went down to nursing at just nap and bedtime. Then it came back at 16 weeks and increased even more recently. DD has even tried to add another nursing session back in the mornings but I noticed it was making her poo softer, so I am discouraging that. I think maybe I'm making colostrum now too.
On one hand, I want to tandem nurse, but on the other I feel like she is ready to wean and that the only reason she's holding onto it is because of needing it to fall asleep. I know that she needs to be able to go to sleep without me, especially with the baby coming soon. Last night I nursed her in her bed after reading some books and then I just couldn't stand it anymore so I rocked her. I rocked her so long that my back and neck were aching, but it wasn't enough for her. We ended up lying back down in bed, but I refused to nurse any more. She fussed a little, but actually fell asleep with me rubbing her back (something she has NEVER done!) I tried again tonight and told her ahead of time that I'd nurse her in the chair and then we'd lie down and I'd rub her back so she could fall asleep without nursing again. Nursing was a lot more enjoyable sitting and when I told her it was time to finish, she stopped without me having to pry her teeth off of me for once!
Then we went to bed and I rubbed her back, although she did fuss a little. I reminded her that we were done. It actually didn't take long for her to fall asleep! I am amazed. Recently when nursing was bothering me so much, I'd stop her before she was ready and she'd scream and plead PLEEEASE PLEEEASE PLEEEASE like it was the end of the world. I am so glad she is not doing that because it was hard for me to resist!