Actually, it's not. Nowadays, many girls will choose oversized coats or oversized T-shirts or oversized hoodies. In fact, girls choose loose clothes or large size clothes to make themselves look thinner.
So if a boy wants to look strong, try not to choose too loose clothes, which will only make him look smaller, and when your arms and legs are exposed from the clothes, you will think that this boy is thinner. You can try if you don't believe me. It will definitely scare away girls.
Personally, I suggest choosing clothes with a more neutral style, such as a suit that fits or is a little big, or a solid T with casual pants, or a leisure suit suit.
In addition, if you are an office worker, it is ok to wear a shirt with jeans, as long as you choose a size slightly larger than the clothes you wear every day. This kind of dress will not look dull, nor will it look too thin.
Many people think that it will be easier for fat people to become muscular men, and it will be more difficult for thin people to become muscular men. Actually, it's not.
Thin people themselves have more muscles, and they are more likely to become muscular men and shape a person's figure. So if you are a thin boy, it is suggested to go to the gym to practice more equipment and do less aerobic exercise, because the equipment itself is doing muscle building exercise, and aerobic exercise will only consume your body fat and muscles, so if you want to look stronger, you can only cover it up by wearing it for a while. To really make yourself stronger, you have to go to the gym more!