Sign languages are beautiful languages that people find themselves using by accident. Many official signs are often used as gestures and cheers, and it's good to know when you think you're rooting for Oregon when you're actually emphasizing "vagina."
Thankfully, sign language users discussed in a thread the signs people use and don't realize that they're using.
You're not alone if you mess up "thank you" and "screw you."
I took sign language for three years at high school. Our principal would incorrectly sign the word “thank you”, and would instead do the sign for the word “slut”. My sign language teacher let her do it for three months before correcting her.
The University of Oregon's sports fans have a lot of spirit, and they like to put their hands together in an "O" and cheer. Unfortunately, many of them put their hands together in the wrong way and you have half a stadium signing "vagina" and shouting an extended "oh" in excitement.