Eating a burger with a fork and knife is generally considered unusual or "weird" because burgers are traditionally regarded as a casual, handheld food meant to be eaten with the hands. Burgers are often associated with informality, outdoor events, fast food culture, and a relaxed dining experience.
Using utensils like a fork and knife to eat a burger can be seen as formal or overly fussy, deviating from the customary way of enjoying this type of food. It may also be viewed as unnecessary since burgers are designed to be easily eaten with the hands, eliminating the need for utensils.
The cultural norms and perceptions surrounding food etiquette can vary across different regions and social contexts. In some situations, such as in upscale restaurants or if the burger is exceptionally messy or topped with elaborate ingredients, using utensils to eat a burger might be more acceptable. However, in most casual or fast-food settings, using utensils for a burger can draw attention and potentially be seen as an odd or pretentious choice.
Ultimately, the choice of how to eat a burger is a matter of personal preference. It's important to be aware of the cultural context and expectations of the dining situation. If you prefer to eat a burger with a fork and knife, it's perfectly fine to do so, but be prepared for potential reactions or comments from others who may consider it unconventional.