(CNN)Abby Mahler ended a childhood friendship in the comments of one of her Instagram posts.
"You do not get to like this post with (the) amount of restaurants you eat at. [expletive] I mean it," she wrote.
Mahler, 27, has lupus and is immunocompromised. She has spent the past nine months using her social media account to help inform others about the importance of mask-wearing.
But Instagram has also been a window into the day-to-day activities of people who have gone about their lives as if there were no pandemic: eating at restaurants mask-free; going on lavish vacations; hanging out at bars.
So when one of those friends hit "like" on one of her posts, she didn't hold back.
"I have no patience for people who don't think literal rules apply to them," Mahler told CNN. "And for people who don't have an understanding about the disconnect between their behavior and reality."
Relationships, like the one between Mahler and her childhood friend, have been tested during the pandemic.
While the first few months led to Zoom hangouts and remote celebrations, deepening and visible divisions in how people are handling the ongoing pandemic have become the source of growing tension -- and sometimes outright conflict.
Some have said their relationships have strengthened during this time, as they have prioritized whom they care about and how often they check in.
But as 2020 comes to an end, others say distance, as well as differences in how their friends handle the pandemic, has changed their relationships -- and not necessarily for the better.
"A lot of relationships right now are struggling with how people are responding to the pandemic differently," Shasta Nelson, an author and friendship expert, told CNN earlier this year.
They feel judged, she said -- or they feel guilty, or they feel judgmental.
For some, their values no longer align
Like Mahler, 33-year-old Manisha Jogia found herself at odds with one of her friends during the pandemic.
In August, she said her friend had told her he was breaking away from his pandemic bubble to hook up with girls he met online. When Jogia, who is from Los Angeles, called him out, she said he brought up the Black Lives Matter protests she'd attended.
"We were just talking about it and one thing led to another, and we both sort of started pointing fingers at each other," she told CNN.
"Everyone's just doing what they think is right during the pandemic. ... Everyone's flexible in their own ways. I was going to the protests, for example. And he was calling me out for that. He was like, 'I feel like what you're doing is worse.'"
After she cooled down, Jogia said she reached back out to him. But she didn't hear back -- until her friend sent her an email, ending their relationship for good.
"He essentially just said I'm not interested in continuing a friendship with someone who judges based on my actions or whatever," Jogia said.
"For me, I was like, I'm going to cut my loss here. Because I feel like people are really revealing themselves right now. I feel like I've seen a lot of people who I loved and respected be really selfish ... and I don't have time to surround myself with people who are not going to care about other people."
For others, it's not differences -- but distance
Even some people whose values still align with those of their friends have found their relationships suffering during the pandemic.
The reason for their drift is not rooted in ideological differences, but rather distance.
While video calls over Zoom or Facetime have helped, many have said that after spending most of the year staring at a screen, they've had enough.
Martin Odima Jr. sits through six to eight video calls a day using three different video conferencing platforms. He's a special education teacher, coach and adjunct faculty member at a university in Minneapolis.
His 7-year-old daughter is among the many students nationwide who are doing virtual learning. So, he said, the two of them are glued to screens all day.
When his friends plan a Zoom meeting to play games and catch up, he finds it difficult to join in.
"It's hard to 'show up' and actively pursue social activities with my friends online since I am doing it all day," he told CNN. "I am definitely tired after doing virtual meetings and it takes a while to acclimate back to reality."
Odima said he used to get headaches from so much screen time. Now, he forces himself to plan five to 10 minute breaks in between his daily work calls so he can take quick walk or exercise.