Am i wrong?

My husband claims a child that's not biologically his. He's on the birth certificate and the child has his last name. The mother of the child moved on more than 3 yrs ago, he hasn't seen the child. She married and the child now calls that person "dad". My husband was there for the pregnancy n first 2 yrs of the child's life, but no longer sees her, talks to her, or even tries. He keeps the ultra sound in his wallet and the hospital bracelets in his dresser drawer. Am I wrong for this bothering me so much?. It's not his kid, and he hasn't seen or talked to either of them in YEARS!.