The early Church brethren would tell Bill to hold their mild barley drinks.
After all, Joseph Smith married two 14 year-olds, Brigham Young married many teenagers including a 13 year-old, John Taylor married a 19 year-old, Wilford Woodruff married a 15 year-old, Lorenzo Snow married two 16 year-olds, and Joseph F. Smith married an 18 year-old.
Different times? Maybe a little, but come on. The average age of first marriages for women was 22.9 years old (not too much younger than today's average age of 28). Not 13.
At least Bill's girlfriend is old enough to know what she wants. And, at least our early leaders didn't abandon their wives.