For the past few months, Kelly Knock has been vigilant about enforcing quarantine rules. But as restrictions relaxed, the discussions with her husband, Darrell Glaser, surrounding the safety of their two children, ages 3 and 6, became more strained.

"When it was just our little bubble, we were both doing OK. We could manage our situation," said the Baltimore resident. "But now that our bubble is overlapping with other bubbles, there's just more to disagree on."

So when the kids have a play date, Knock insists on masks, and Glaser does not. When her 6-year-old son has a socially distanced bike ride with friends, she's constantly saying "back up" while her husband is silent.

"Sometimes, I wonder if it would be less stressful not to have a play date at all," she said.

Now that many parks, child care, camps and other businesses are reopening, what happens when you and your spouse can't see eye to eye? How do you navigate this murky new stage? Who gets to decide if, after almost 12 weeks at home, one partner wants to attend brunch with all the relatives, but the other says it's too soon?

In the early weeks of the crisis, when everything was closed and streets were empty, it was easier for partners to agree. A global pandemic isn't like other parenting issues — say, screen time or curfew — because these decisions can be a matter of life and death.

Ben Karney, a professor of social psychology at UCLA, says that even when emotions run high, couples can bridge their differences constructively. The key? Start from the point that you both have legitimate preferences.

"Now, you're in a negotiation, not a debate," he said. "It's still not easy, but it's better than a debate, when you try to convince your partner that what they are feeling is wrong."

These are two different preferences, albeit with higher stakes, Karney said.

In the case of the brunch gathering, he gives an example, starting with the more risk-averse mom acknowledging dad's feelings; that she understands he really wants to attend.

Dad might respond: "This time, I won't go. I get that it makes you anxious and I will prioritize your feelings over my desires."

Or an equally valid response from Dad could be: "I get that you'd rather I didn't go — and I know it will upset you. I'm not saying you're right or wrong ... But, this time, I am asking you to make this sacrifice for me."

When separation, divorce and stepparents are added to the mix, discussions over resuming activities can become even more complicated.

Mary Owen married Mark Thomas two years ago, and was quite certain she had the necessary skills to steer clear of conflicts, not only with her husband, but also with her two stepdaughters, now 3 and 7.

But then the virus came along, making it more difficult to get on the same page, especially about shuttling the kids back and forth between their homes.

Recently, the couple clashed over attending his older daughter's birthday party. Owen knew there would be a crowd and that safety protocols would be nonexistent, so she asked Thomas to decline.

"I lost," she said. "The virus has just exacerbated everything. Also, in divorce, I think there's a lot of guilt. Mark is a really good father and finds it hard to say no. But there are times I want to say, 'Wait, what about me?' I live here, too."

Dr. David L. Hill is a pediatrician and co-author of the new book "Co-Parenting Through Separation and Divorce" with Jann Blackstone, a retired child custody mediator in California. They recommend starting difficult conversations by envisioning the relationship you would like to have with your child's co-parent in 20 years. Imagine graduation or a wedding day. Then, ask yourself: "What can I do today to achieve that vision?"

Hill speaks from personal as well as professional experience. He has two sons, now 15 and 18, from his first marriage. His second wife has an immunodeficiency, so the most prudent course of action during the pandemic has been for Hill to forfeit weekend visits with the boys — for now.

"Even in these sad and scary times, keeping your focus on the kids helps parents step out of all the pain and anger that occurs around separation and divorce," he explained. "It helps you pull back and gain some perspective."

For her part, Knock finds herself carefully picking and choosing her battles, although lately, whenever things get too tense, she says she's the one most likely to concede.

"With all that's going on, we just can't afford to disagree right now. I just want to keep the peace."