Bangla men and men holding hands means friends. Notice that no or very few Banglas or Indians hold hands with women even if their wives. Chinese men always insist on holding hands with their women whether GFs or wives. If the man becomes not interested in holding hands with her, the GF or wife can start worrying about possibility of breakup or divorce. It's a signal to public that "the girl is mine." Westerners are a bit in between, not so concerned about holding hands or not. But if two western men hold men, you can bet your bottom dollar that they're gay lovers. The usual western practice of signalling to public that the two (man and woman) are a couple is the woman clinging to the arm of her man, popularly adopted practice in contemporary Chinese culture too. Traditional Japanese men are the best. The woman must walk behind her man and keep following and pacing without asking where he's going and just keep following. That was actually the ancient Chinese practice too, that the Japanese learned and adopted. However, this practice has also been diluted somewhat by influence from contemporary western and Chinese practices.