Older Sister Did Feet Porn

Honestly shook, I don't personally watch porn so it's not like that. A friend of mine from my school days often watches pornography on his free time and one day while I was at work I got a text saying how he'd just seen my sister. I thought he was trying to be annoying so I told him to show me proof or shut up. He then sent me a link showing everything. My older sister looked to be in her university days. Videos included her huge soles giving footjobs to being worshipped or sole jois to tickling. Some of the people involved I recognized. One was her English teacher whom was also my teacher.
Not sure how to process it