boyfriend and female underwear

Yare
Hello ladies, so today I was doing laundry and asked my boyfriend to fold my underwear and he asked how my butt fit in those under wear. I didn't mind because I have a big  butt and pretty tiny underwear. Then he said. I wonder what my balls look like in these. And later that same day we were about to have sex and he said can I see how my balls look In your underwear. And I said no since for me it's just a turnoff. Should I be worried that he asked me to wear them ? Can you guys share some experiences or advice ?