Guys make fun of other guys' legs for many reasons. They may find the legs ugly, too small, too large or are feeling insecure about themselves.
Guys may make fun of another guys legs because they are jealous.
Guys may make fun of other guy's legs because they are jealous.
A guy may make fun of another persons legs because they like them.
Maybe guys don't make fun of a guy's arms because there is nothing to make fun of.
Because guys have things between their legs that they have to give room to!
Because they're guys. Making fun of each other is part of what guys do. It's probably got something to do with social dominance instincts: "If I can make my competitors for mates seem less attractive, it will make me seem more attractive by comparison, allowing me to get a more desirable mate." Why legs specifically ... probably because the guy being made fun of has "funny-looking" legs and the guys who are doing the making fun feel particularly confident of their own legs. It could be ears, or hair, or teeth, or really anything; guys tend to go for the low-hanging fruit in these matters.
Guys may make fun of your legs, but not your arms because they are jealous of your legs.
If girls tell you that your legs are cute and guys make fun of them, the guys may be jealous of your cute legs.
Guys make fun of each other in a playful way. They just may be joking around with you, try asking them.
because they get nevous
Because it looks ridiculous on a guy.
Depends on the guy because some of them will play with your legs and don't want to feel any hair and other guys want you to have hair to make them feel better about themselves. But all guys are different.