The Aerosmith rocker proposed to Erin on Christmas Day (25.12.11) during a vacation to Hawaii and wanted to surprise her so he slipped the one-of-a-kind band into a gift she had given him earlier.
He told TV show 'Entertainment Tonight': "It was Christmas morning and her father was there, down from Alaska, and I hid it in a box ... she had given me, full of all these little things.
"I slipped it in there the night before, so when I got to bottom I said, 'What's this?'
"It was the perfect time, a perfect moment."
Steven - who has been married twice before - says he felt the time was right to propose because he was getting a bit too big-headed because of his success as a judge on 'American Idol'.
He added: "I did this for myself too; it grounded me a little bit. You tend to get a little lofty being on tour and doing 'American Idol'."