AceShowbiz - Peter Facinelli feels like he's learning how to be a parent again since welcoming his first son. "The Twilight Saga" actor became a dad for the fourth time in early September when his partner Lily Anne Harrison gave birth to a baby boy and Peter, who shares three daughters Luca, 25, Lola, 19, and Fiona, 16, with ex Jennie Garth, says it's very different to raising girls.

Speaking to PEOPLE at The Barbara Berlanti Heroes Gala in Santa Monica, California on Saturday, October 1, he explained, "I've had three girls, so having a boy is interesting because I'm not used to it. I have three sisters and I have three daughters, so it's interesting being a new dad to a boy," he continued. "It feels like I'm starting ... Not only starting over, but starting with something new to learn from. He's teaching me a lot, too."

The actor went on to reveal he's been using a product called a Pee-Pee Teepee to avoid getting squirted in the face when changing his little boy's nappy. Peter also explained he is trying not to think too far ahead into his son's future, adding, "I don't know who he's going to be or what he wants to be, so I think you always have ideas in your head of, 'Oh, baseball and soccer.' But my daughters were very athletic too, so just take one day at a time to see what he likes."

Peter and Lily have yet to reveal their son's name and the actor previously explained they were waiting to meet the new arrival before deciding. He said, "We have a few names picked out but we are waiting to meet the little one."