We all want to think about breastfeeding in a loving way. With halos and angels and soft sweet music playing while a mother calmly nurses her newborn. In our minds (mom's head), it IS that way. To anyone else, it can get quite messy and downright disgusting.
Yup, I said it. Breastfeeding can be gross. Not the act of breastfeeding. That's natural. But sometimes babies spit up and that's - kinda gross. Or, like in my case, my nursing toddler wasn't used to having unlimited access to my engorged milk supply, had way too much, then promptly vomited all over me. Doh.
For any first time tandem nursing mothers out there, don't rush to wean your toddler. Step back, and give it time. The older nursling is not used to having so much milk at once. And it's very likely they are super excited to have all that milk available to them. They try (and often succeed) at draining an engorged breast. Which is a lot to take in a short time. But don't despair! With a little patience and understanding from you, they will get better at nursing again.
Desmond had a particularly rough time when my milk came in. He vomited almost every time he nursed that week. He was nursing 2 or 3 times a day. I got better at having cleanup supplies within my reach. I only offered one boob each nursing session and suggested we stop when I felt my breast was mostly empty. Desmond got better at knowing when he had enough. At first he would only nurse on the one side. Then once my milk production started to regulate itself better, he would ask to nurse on the second side. He hasn't gotten sick in a few days now.
So don't rush off to wean your nursing toddler. Wait and see what happens instead. Kids learn so quick and so much if we let them. Roll with the mess and I assure you it will be over before you know it!