Name on birth certificate

My friend is only 9 weeks pregnant and not with her baby father. She's 19 he's 15.... Yeah. Well. She told me she's gonna have her new boyfriend of only 6 days sign the birth certificate she still has months. I see it as she should leave it blank and when she gets married her man can adopt it until then I think it's wrong. What would you tell her? I told her not to as that's not that boys responsiblity, he can be there for them and help but don't make him sign. She said "I want what's best for my baby". Lol time to grow up. I'm 17 weeks my baby daddy won't be signing but no way is any other man signing either.