United Kingdom, March 4 -- Demi Lovato has suggested her relationship with Wilmer Valderrama was "not OK".

The Confident singer was just 18 when she started dating the That 70s Show actor in 2010, when he was 29, and they were together for six years, but now Demi has bonded with fellow former child star Keke Palmer over the relationships they had in their teens which felt grown-up at the time but now they don't think were appropriate.

With Demi as the guest on her Baby, This Is Keke Palmer podcast, the 32-year-old host said: "I feel like people don't understand that that's what we was dealing with, you know? I found myself dating. I'm 15. Why is my boyfriend 20?"

Demi replied: "Why was my boyfriend 30? You know what I'm saying?

"But t...