Should I Tell My BF?

The other day, my bf was furloughed from his job. As anyone would be, he was very upset. However, when he came to my home, I was in the middle of studying, getting ready to take an exam. He knew this, but the way he was acting upset my older sister. He had a really bad attitude & kept leaving, going in & out.

Once he left for good, my sister said she didn’t appreciate how he was acting, especially because he knew I was studying. She said he should have just went home. She said it wasn’t fair to me.

My question is, should I tell him how she felt? & let him know to not do that anymore? I don’t want to cause any problems between him & her, but I felt that she was right about the whole thing. What would you do?