Pop princess Britney Spears refuses to give up her career to be a stay-at-home-mother, because her baby is happier when she sings. The TOXIC star, who last night (09MAY06) announced she is pregnant with her second child with husband KEVIN FEDERLINE, claims her singing and dancing has a positive effect on son Sean Preston. And even though she is determined not to give up her career until she feels the time is right, Spears insists she would never neglect her children because of work. She says, "I genuinely love to sing and dance. When I get in a creative mood, I can't shut up. It's the craziest thing. "At one point I was thinking of being a home mom, but when my son sees me dance he lights up. Then I know what I'm supposed to be doing - if Mom's happy, baby's happy! "I've been meeting with different people to work on the album and looking at different (movie) scripts. "But I've mainly been concentrating on my son."