17 year old dating a 26 year old?

Why do many people think it's wrong? we've been dating for a year and a half. very much in love. My mom let me move in with him 10months ago after being emancipated. I already graduated highschool last year. and we're expecting a baby girl in March and he's been very helpful my whole pregnancy. I'll be 18 in June. So my question is why are there so many people telling me a guy that age would only want sex with a girl my age? That's not true, from day one he has been nothing but a great guy. And I'm tired of people thinking he's some kind of sick child Molester!