Blue hippo tang vs porcupine fish

Hello everyone.. maybe someone can help me. I have a 55gal with a hippo tang, diamond goby and a clown fish. I had my sick porcupine fish in a QT tank for a month. I added Bloat ( porcupine fish ) to my display tank. And his is very interactive with my husband and I when we get close to the tank. But now my tang, who always kept her distance, now get jealous. She swims up to Bloat, opens her mouth and lays sideways. Should I be concerned?? She does not act like that with any other fish, only when she see's Bloat in front of tank, wanting attention.. I've been trying to read everything I can find, and still no real answer... please help me... Thank you