Boppy lounger?

How long did your baby fit on the boppy lounger?

I bought my son an elephant pillow to lay on that’s kind of like the lounger but I feel he’s getting too long for it and he’s only a month. Another thing with his pillow is, I have to put him the opposite way that it goes for his head to be more up than his bottom. It’s frustrating because I feel he slips down eventually.