Outraged flight passengers are complaining this week that three rambunctious children were left unsupervised in coach while the parents sat comfortably in first class, according to a viral Reddit post."United is now offering free babysitting," a passenger joked in the social media post, describing an apparently chaotic United Airlines flight from Houston to Fort Lauderdale.The children — whose estimated ages were 7, 9 and 10 — sat in row 8, according to the post. The observer speculated that the parents were "upgraded to first class," leaving the little ones behind as the adults relaxed on their own up front.ACTOR AND FORMER 'SNL' STAR SLAMS MAJOR AIRLINE FOR HIS SEAT DOWNGRADE: ‘I PAID FOR FIRST CLASS’"Thirty minutes before landing — the boys start pounding on each other — punches, choking each other, super-loud talking to the point of almost screaming. The little girl ends up with as much slack in her seat belt as possible," the poster on Reddit wrote."Parents are upgraded, so [they] had a nice, relaxing flight while a select few of us kept an eye on the misbehaved children," the United passenger suggested to others on Reddit."At what point should the flight attendant have stepped in and requested the parents realign to supervise their children?" the user added.Fox News Digital reached out to United Airlines for comment.FAMILY OUTRAGED AFTER MAJOR AIRLINE SEATS TODDLER APART FROM PARENTS, SPARKING VIRAL DEBATESeveral commenters on Reddit weighed in on the flight drama."There are two types of parents: Those who actually parent, and then those who are nothing more than bad camp counselors who want to clock out when their shift is done," one person said.Another said, "If that happened, one parent has to stay with the children, and one child gets upgraded or nobody is upgraded. Some people can be so selfish."CLICK HERE FOR MORE LIFESTYLE STORIES"I would have gone up to first and — loudly — fetched the dad," yet another person wrote. Others felt the angry passengers should have spoken up about the issue to flight attendants."Why didn’t someone just push the call button?" one Reddit user wrote."Just ring your call bell, and when the flight attendant arrives, point over to them and put your headphones back on," another quipped.Etiquette expert Jacqueline Whitmore of Florida told Fox News Digital that children under age 12 should generally not be left unsupervised on a flight."I think a parent should have stayed back with them because of their age," she said. TEST YOURSELF WITH OUR LATEST LIFESTYLE QUIZWhitmore said, in these cases, a flight attendant should ask the children where the parents are, and a parent should be notified."That's what flight attendants are there for — safety and to keep peace in the cabin," she said.She also noted that many children struggle to stay in their seats on long flights."Some children listen, some don't," she said. "Most children in a confined area are very uncomfortable. They want to run up and down the aisles. That's just what children do."The U.S. Department of Transportation encourages airlines to seat young children next to a parent or accompanying adult at no additional charge, according to the agency’s website.CLICK HERE TO SIGN UP FOR OUR LIFESTYLE NEWSLETTERFederal regulations, however, do not currently require airlines to guarantee adjacent seating.The department maintains an online dashboard that outlines which carriers commit to seating children age 13 and under next to an accompanying adult without an added fee.Some major carriers do not commit to providing fee-free guaranteed adjacent seating, including Delta, Spirit, Allegiant and United, according to the DOT dashboard.Several airlines, however, state that they will seat children ages 13 and under next to an accompanying adult at no additional cost under certain conditions. Those carriers include Alaska Airlines, American Airlines, Frontier, Hawaiian Airlines and JetBlue.Kelly McGreal of Fox News Digital contributed reporting.