1. When choosing underwear, consider your boyfriend's height of 175cm and weight of 140lbs.
2. For his height, an XXL size is typically recommended for underwear.
3. His weight of 140lbs should be evenly distributed, but the underwear size may need to be adjusted according to his body type.
4. Pay attention to the fit of the underwear to avoid it being too tight or too loose.
5. Refer to the underwear size chart and consider your boyfriend's actual comfort level.
6. If his current underwear size fits well, you can continue to purchase the same style or a similar one.
7. If you want to try a new style or brand, you can moderately adjust the size, but ensure it is close to his current size.
8. The appropriate size is crucial for a comfortable wearing experience.
