No such thing as twin siblings.
I met a set of twins recently who are brothers. As the older twin introduced me to his younger twin, He said, “oh, that’s my twin brother.” I looked at him and stated, “that is just your brother. He looked at me with a “stupid” face and just stood there for a moment. I knew he didn’t understand what I meant, so I explained it.
I said, “Yes, that is your twin, but you are still brothers regardless. Look at it…