'If you don't plan on just sleeping with
her, then no. And when I say just
sleeping with her, I mean "hitting it
and quitting it." 'Cause that shit's just
shallow. A lot of good women (I'm imagining here, so bear with me) don't like to be called sexy all the time, because it's kind of a shallow thing to do. It's just like saying "I find you very attractive and my primary objective in talking to you right now is to have sex with you as soon and as hard as possible."
Unless the feeling's mutual, then it's
different. Work that silver tongue, in
that case. If you're in a relationship though, then you should say it whenever your girl needs a little reminder. I think a lot of girls need to hear that from the GUY THAT'S ALREADY HAVING SEX WITH THEM. There's a big difference from hearing it from some dude at the bar and hearing it from the guy who knows he can already sleep with you' {this was said by a guy on Quora}

A woman has this to say:-

'Telling her this gives you something
(the opportunity to reach out to a hot
and sexy woman) but takes from her
(she feels objectified). Try a mutually
beneficial statement instead: "you
look beautiful", or "you look stunning", which is complimentary without objectifying. Then move on immediately, so she does not feel like you are trying to take anything more
from her. And trust me, if she
appreciated it, eye contact can tell
you that later in the evening'.

Ubunja
Queensuccubus

https://www.quora.com/Is-it-wrong-for-a-man-to-tell-a-woman-how-hot-and-incredibly-sexy-she-looks

lalasticlala, i think guys need to know this