He doesn't mention it (with your help)

You use your power to prevent Superman from mentioning Supergirl's slutty costume, even though he has obviously noticed. He tries his best to to maintain eye contact. "I have your assignment for today right here." He says, gesturing to one of the monitors.

"Oh good, lets see!" Supergirl eagerly says as she brushes past him to look at the monitor. She puts her hands on the desk and leans over to get a better look. Superman tries his best not to look as his cousins skirt rides up showing him her tight ass. "What's going on down there?" She asks after a brief period of silence.