Although the duo never officially confirmed their relationship, sources tell Us Weekly that the pair "are no longer hooking up."
In November, Lovato, 19, and Valderrama, 31, were spotted making out in front of the 70's Show star's L.A. home. Sources tell Us that the pair reunited on several occasions after Lovato was released from a treatment facility in January 2011.
Tuesday morning, Lovato tweeted that "the smartest thing a woman can ever learn is to never need a man."
The former Disney starlet was also "hooking up" with Ryan Philippe, 37, in 2011, but insiders told Us the pair were "nothing serious."
Valderrama infamously told Howard Stern in 2006 about taking Mandy Moore's virginity, and also told the radio show host Ashlee Simpson was "a screamer." He dated Lindsay Lohan in 2004.
- Demi Lovato
- Wilmer Valderrama