| I think the likelihood of a girl taking sex as meaning "absolutely nothing" is far far far lower than the likelihood of a guy feeling the same way.  Girls aren't usually into meaningless sex....at least not the girls I've known.
 I wouldn't necessarily say that cuddling is reserved only for relationships.  I personally wouldn't think anything of it to see two girls cuddle.  I think girls are a lot more physical with their friendships than are guys, and I could easily see a girl having a bad day and a girlfriend cuddling her for comfort, at least.  Equally I can see a mother or father cuddling a child.  I can see people cuddling with their dogs and even cats if the cat will stick around long enough.
 
 There becomes a point where a friend is more than a friend but still not someone you're in a "relationship" with, although technically you are in a relationship with the person.  As far as guys with g/f's, I'd say that's a respect thing.  But I've had girl friends who I'd cuddle with if they wanted and think of it as no more than a close friendship.  If she had a b/f or me a g/f I wouldn't do it out of respect for the significant other, though.
 
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