They all mean attractive. The only different is how they are attractive.
Hot and sexy are pretty close to the same thing. The main difference is between those two and cute. Hot and sexy usually side more with pure sex appeal. The more toned, tan, athletic types. Cute has more of a 'I never want to stop hugging you' effect. They can be the homey, bookish, cuddly people.
I think cute is someone who is good looking and has a great personality. If I don't know they're personality, I'd probably consider them hot. And I never have described someone as sexy so I'm not sure what it means to me.
I have no idea.. I often get called cute/adorable but apparently I'm sexy, and I get called hot.. which to me makes no sense. How can you be all three? Not trying to sound full of myself, just going by on what others have said!
Simply put, in the category of sexual appeal, it's all about the body type and personality.
Sexy- The type of girl who regardless of just about anything, the first thing you think of when you see them is sex. Their body language, verbal language, behavior: it only makes you think of one thing.
Hott- Usually the athletic and really well toned girls. You see something that you like and keep thinking about it for the rest of the day.
Cute- The girls who are good for relationships. The ones who can be anywhere from awesome a-bit-more-than-friends to just girls you want to spend time with.
Which one a girl falls into completely depends on the guy, and since each category is defferent and not better than the others, it can be any combination.