You can temporarily gain the Well Rested perk, adding +10% experience, by sleeping in an owned bed. You can instead temporarily gain the Lover's Embrace perk, adding +15% experience, by sleeping in any bed with a romantic companion nearby.
How long do these bonuses last?
I've heard 12 hours, which is listed on both those Nukapedia pages, but it doesn't always seem to be true. Checking the in-game clock, I've fast traveled to somewhere less than 7 hours away and lost the bonus.
What actions will cause them to end prematurely?
I know that sleeping in any bed will you cause you to lose Well Rested. Will anything else cause these perks to end early?
Best Answer
I tested Lover's Embrace by getting the perk in Sanctuary, noting the time, and then traveling to various locations. In every instance, I still had the perk less than 8 hours from getting it, and didn't after more than 8 hours.
For example, the Boston Airport is more than 8 hours away. I lose the bonus when I fast travel there. Bunker Hill is less than 8 hours away. I still have the bonus when I travel there. If I travel to Bunker Hill, and then to the Boston Airport, I have the bonus at Bunker Hill, but have lost it by the time I reach the Airport.
Therefore, Lover's Embrace lasts for 8 hours. I assume Well-Rested lasts the same.