Los Angeles: Demi Lovato has reportedly been dating actor Ryan Phillipe, but things have taken a back seat after it was alleged that he is the father of his ex-girlfriend Alexis Knapp`s newborn.
The 18-year-old singer-actress was not aware that Phillipe was going to become a father for the third time, according to sources.
The actor already has two children, Ava Elizabeth, 11, and Deacon Reese, seven, with ex-wife Reese Witherspoon, reported E! Online.
"It was really hot and heavy for a while, until it basically happened. It kind of threw her for a loop," a source said.
The `Stop-Loss` actor stood by Knapp during her labour, although it is yet to be confirmed whether he is the father and is waiting for results of the paternity test.
"He is a good father, and whether this is his baby or not, he wants to do the right thing and be supportive," a source said.
Phillipe is also said to have had an on/off relationship with actress Amanda Seyfried earlier this year.