Lamas is the daughter of Lorenzo Lamas and Michele Cathy Smith. Her father is the son of the late Argentine actor Fernando Lamas and the U.S.-born actress of Norwegian descent, Arlene Dahl. She is currently engaged to Matt Grant. Matt and Shayne have announced their Vegas wedding which will occur the weekend of June 7, 2008. Matt Grant explained to TMZ outside of a restaurant in Los Angeles that he is also not in it just so he can remain in America. An earlier scandal was reported on by TMZ that Grant had expressed that he really wanted to remain in America and would marry Shayne Lamas for the green card. He denies that accusation and claims that the whole story was ridiculous. Shayne's best friend, Danielle Rose Krueger, is said to be starring in Lamas newest upcoming movie. 
