Levi Johnston Celebrates Baby Tripp's First Birthday!

Levi Johnston is a first-time dad experiencing the joys of fatherhood, and he's invited ET along to Alaska to help celebrate his baby Tripp's first birthday!

The father of Sarah Palin's grandson was surrounded by his side of the family, including aunt Mercede and grandma Sherry, who loved every minute of her time with her grandson. Sherry must spend almost all her hours confined to her own home -- the result of her guilty plea on a drug possession charge. She is allowed just four hours a week outside her house.

"I feel very bad for that, but the only thing I can do is make up for it," she says.