While Ashton Kutcher is viewed as the hunk of the now-defunct 'That '70s Show,' it's his co-star Wilmer Valderrama who is truly the chick magnet, having dated Demi Lovato, Lindsay Lohan, Mandy Moore and, well, more! Rumors are circulating that the actor and Lovato, 21, are about to get engaged, and there's interesting evidence to suggest this may be the case.

Valderrama, 33, was spotted buying a ring at Tiffany in Pasadena back in November, with a Tiffany store employee saying that the actor did indeed purchase a rock at the location -- and that he exhibited signs of a man about to propose. Well, they would know the signs and the posturing, since they sell rings for this occasion on the regular.

The store attendant said, "He chose a really classic, beautiful ring. Demi is going to be a happy girl when she gets it. He didn’t say what it was for, but he was really excited and happy -- he seemed like any other guy getting ready to pop the question."

That's a big leap for the Tiffany employee to make, but Valderrama was spotted buying a ring, which elevates this story a level above regular ol' gossip.

Lovato and Valderrama -- Dilmer? Demer? Lovaterrama? This one is tough! -- are said to have rekindled their relationship this year, with him posting a tweet on her birthday in August, suggesting they were loved up. They hooked up in 2010 after she split with Joe Jonas.

Maybe he likes it and is puttin' a ring on it.