We asked six elderly couples how they’ve kept that spark going for so many years. Here’s what they told us.

1. Don and Ellen Adler, 51 years

“It’s important to take time apart. We’ve been married for five decades; of those, we’ve spent every other decade completely separate. He’ll join the Merchant Marine while I’ll live in a cavern, or we’ll just start walking in opposite directions and meet back up once we’ve gone the whole way around. Then we pick up right where we’d left off and finish whatever conversation we’d been having. Last time it was about hothouse tomatoes, if I recall.”

2. Grace and Albert Iscoe, 55 years

“We’d be nothing without our shaman. Grace and I used to bicker constantly about this or that—petty things. Finally, it got to be too much. We decided that enough was enough, and traveled deep into the heart of the jungle in search of the shaman we’d only heard spoken of in low whispers. He boiled our wedding rings with snake eggs and a blind hog in a clay stew pot, drank it all down, and spoke aloud the name of a ghost spirit from the world before this one. After that, things really just fell into place.”

3. Carmen and Carl Barnes, 46 years

“Keep things surprising! For the first few years we were married, whenever we’d set a date night, Carl would show up with more teeth than he had before. Sometimes only one, other times a whole pearly bunch. No matter what, it was a thrill. It seemed like there was no limit to how many teeth he could have. That kept things exciting for a long time, and when it began to get staid, he started showing up with fewer teeth, or bigger ones, or little tiny baby’s teeth. Well, that’s been carrying us through till today.”

4. Julia and Frank Price, 43 years

“We’ve lived in the same house since we were married. Frank built it himself, on what’s turned out to be an incredibly unstable electromagnetic anomaly. Time will skip forward and backward, and we’ll snap into consciousness in our 20s, or withered and decrepit, but always disoriented, nauseous, and howling. Then, bam, it’ll be 1995 again. Our lives apparently continue without us, and I guess whatever we’re doing in our marriage seems to be working. Oh, God, here it comes.”

5. Gerald and Eleanor Kim, 55 years

“It’s a cliché, but communication is key. We spent decades deciphering ancient pottery fragments predating the legendary Tower of Babel to discover the one true Language man was given by God to speak perfect truths. Now, we can already visualize everything we’ll hear from each other before we speak, and flowers lean toward the sounds of our voices. It doesn’t work over the phone, though.”

6. Miles and Leslie Greene, 60 years

“We both learned to do a flip. If one of us is unhappy, the other one does a flip, and vice versa. We would recommend you learn to do a flip.”