The 29-year-old shared the story on Reddit where it received thousands of upvotes and comments.
The groom-to-be wrote: "For background, my parents got divorced when I was 5. The divorce happened after my dad fell in love with his current wife and my stepmom Alice.
"They claim they didn't cheat but waited to be separated before anything physical happened. I don't know or need to know whether that's true at this point. My dad and Alice got married and were living together by the time I was 7," the Redditor added.
His parents shared joint custody as their son grew up, and the Reddit poster explained that Alice was "100 percent a mother figure to me," adding that: "We are very close, she's been there for me for every tough moment of my life. She also helped pay for my college and grad school which I'm extremely appreciative of."
While planning the first dances, the couple had arranged their own first dance, a father-daughter dance for the bride, and, when it came to the groom's family, decided upon two dances—one with the man's mom, and the other with his stepmom, Alice.
"I really don't feel right excluding her and only doing a dance with my mom, so I asked her if she'd be comfortable doing one with me as well. She was overjoyed and cried with emotion," the poster wrote. "I'm really excited for it. But once my mom found out, she flipped out."
Hurt by the addition of the dance with his stepmom, the man's mom expressed her upset: "[She] said I'm replacing her like my dad replaced her. I told her it's not a replacement but she's been so supportive of me my entire life and I consider her my 'bonus mother' so I don't want to exclude her."
The relationship-expert duo behind Decoding Couples, Rachel Facio and Stacey Sherrell, offer free relationship advice and coaching on the adult-education platform Onomy.co. They told Newsweek: "Blending families means blending very different people, worlds, and cultures on purpose from a place of love.
"As a result, there are going to be misunderstandings, miscommunications, conflict, and fallouts when we blend those different people from those worlds."
The poster wrote that other members of his mom's family had told him he was in the wrong to have the dance, but explained: "I know it's a little controversial but in my heart, it's what I really want to do."
In more than 4,000 comments, Redditors were quick to tell the poster that he was wrong to have the dance with his stepmom. One wrote: "You're doing something knowing it will hurt your mother. That's your choice, if a dance means more to you than someone else's feelings, go for it."
Another Redditor commented: "Dancing with your father's affair partner at your wedding is a low blow to your mother," while another posted: "Imagine your future wife cheats on you with another man. And then twenty years later, your daughter wants to dance with him at her wedding."
"The groom-to-be could start with acknowledging that the blending of these different families is hard on a day he is creating his own new family," said experts Rachel and Stacey. "We'd tell him to put it right out there in the open and share how he feels about all these important people in his family."
Meanwhile, some Reddit users agreed that the poster should follow what he wants for his wedding day. One commenter said: "Whether or not his dad cheated doesn't erase the 20 years of relationship he built with stepmom. It's clearly not an easy situation. But the answer isn't to pretend like stepmom doesn't exist. This is his wedding."
Another Redditor wrote: "Your step-mom did a lot for you. It would be offensive not to include her, and a second dance with her is perfect in my opinion. You are not replacing your dance with your mother."
"Look, this is your wedding and if you love your stepmother then you should absolutely go ahead with that," read another reply.
"When something is different from what we are used to, we crave and need the understanding to process it," said Rachel and Stacey. "Having an open discussion would hopefully ease the tension and conflict around an otherwise very joyful day and set the groom up for making whatever decision is the most meaningful to him."
Newsweek has reached out to poster u/No-Pressure3284 for comment. We could not verify the details of the case.
If you have a similar family dilemma, let us know via firstname.lastname@example.org. We can ask experts for advice, and your story could be featured on Newsweek.