An American Airlines passenger has sparked a huge online debate after claiming a man sitting beside her removed his shirt, repeatedly touched her and encroached into the seat she had paid extra to upgrade.

Breanna Morello shared her experience on X following the flight, where her post attracted millions of views.

She said she had paid additional money to upgrade her seat but found herself sitting beside a man she estimated weighed more than 300lb.

Morello alleged that the passenger occupied part of her seat and repeatedly made physical contact with her during the journey.

She also claimed he removed his shirt during the flight and complained about his smell.

Passenger says cabin crew did not intervene

Morello claimed she attempted to raise the issue discreetly but said flight attendants did not intervene in the way she had hoped.

Writing online, she questioned why she had paid extra for a seat if she was unable to use the full space.

Her original post rapidly went viral and triggered a wider discussion about airline seating, passenger comfort and how carriers should handle situations where one traveller encroaches into another person’s seat.

American Airlines’ conditions of carriage tell passengers to dress appropriately and state that travellers should ensure their odour is not offensive unless it results from a disability or illness.

American Airlines contacts passenger

Morello later posted that American Airlines had contacted her and asked for additional time to investigate what happened.

She said the airline told her it needed to speak with the flight attendants involved before responding further.

American Airlines has not publicly confirmed Morello’s allegations about the other passenger.

The incident has nevertheless reignited debate online about passenger size, personal space and what obligations airlines have when customers cannot fully use the seats they purchased.