For what GP is talking about, it's per giver. It's a combined gift/estate tax, with the goal of preventing someone from giving to escape their eventual estate tax burden.

But that isn't really relevant for the average person - gifts below the annual exclusion amount (something like $14k) are exempt from reporting/recording/tallying at your death. And this does apply per each pair of people per year, so in your scenario BG would have nothing to report.