How do you get the Papal Bull achievement in CK3?

By God Alone achievement

Papal Bull

Make your Puppet Pope sleep with your spouse

Papal Bull is a Crusader Kings III achievement: Make your Puppet Pope sleep with your spouse. The game groups it as Hard. It comes with By God Alone. Patch 1.20.0.3, from game/common/achievements/ce3_achievements.txt.

Quick answers (1)

How do you get the Papal Bull achievement in CK3?: Make your Puppet Pope sleep with your spouse.

Conditions as the game checks them

Possible decides whether the achievement can still be earned in a run; happened is the check that unlocks it (common/achievements/_achievements.info).

Unlocks when (happened) (4 lines of game script)

custom_description = {
	text = ce3_12_papal_bull_achievement_trigger
	exists = global_var:ce3_12_papal_bull_achievement_unlocked
}

As written in game/common/achievements/ce3_achievements.txt.

The file gives no “possible” condition for this one.

Source: game/common/achievements/ce3_achievements.txt, game/common/achievement_groups.txt and the English localisation, Crusader Kings III 1.20.0.3.