What will happen if my new husband has not filed taxes in four years?

I recently married a man who told me he hasn't filed taxes in 4 years!!! The first year he owed $798. The following year he would have gotten return of $2600. The next year he would have gotten $38. This year if we file jointly we would get around $138. I did the taxes to catch him up but NOW Im scared to file them! HELP!