K.Z.
This reminds us that all kids are wired differently, even twins! To get a better understanding of where this seemingly difficult child is coming from, you should read a book titled "Raising Your Spirited Child" by Mary Sheedy Kurcinka. There is a chapter on sensitivity and many spirited kids have issues with clothing (tags, seams, fabric). If they are still babies, you might start with Dr. Sears' book "The Fussy Baby Book." It addresses the fact that some babies are more fussy (he calls them high needs) than others.
With so many kids in your house, you were bound to have one! The good news is that the high needs kids tend to be MORE in every way, more intense, more passionate, more everything! They will always be that way. You may have to change the way you deal with that child and change your attitude and the way you think about him to be more positive. He will be your most challenging kid, but he may have the most potential, so don't short change him as he grows up.
If he is still a baby, can you wear him in a sling or Ergo carrier while you do things around the house or play with the other children? He may require more touch than the others. If you can work with his needs while meeting the needs of all the kids, you will all be happier. If any of the kids are older, ask them to carry that baby! Most of all realize that your twins are 2 different kids with different needs. The other twin may be getting what he needs already, otherwise would be protesting.
Best of luck, you sure have your hands full!