Why do guys want their friends opinion about a girl?

I have noticed that sometimes when a guy likes a girl and wants to talk to her he always talks to his friends about her first. Like he may ask them, “what do you think about her?”. I mean if you really like the girl then who cares what your friends think! Right? I’am asking this because recently this guy that is my friends cousin he asked his friend what he thinks about me I already know he likes me he makes it very clear I just wanna know why do you need or want your friends opinion, and what if your friends opinion is negative (for example they dont think your attractive or something stupid like that) would you guys take that into consideration? Do you really want to know what your friend thinks? Or do some guys ask their friends that question because they really care about what others think? Or just to make you a topic to talk about because he already knows hes gona ask you out so when his friends say something good about you it makes him feel like hes the man if he goes out with you? I just wanna know why do guys want their friends opinion about a girl?