SHE’S cute, you’re horny; why not throw in a compliment and see what happens? But never one of these:  

‘You’re a MILF’  

If you wish to reaffirm the allure of a lady of slightly more mature vintage, this phrase will spring to mind. It is, however, unsuitable. Any reference to age at all, even in a positive sense, is likely to be receieved badly. You could add that the MILFs in porn are often played by 24-year-olds, but that means yelling about your wanking habits in a nightclub. 

‘I can’t believe you’re [your age]’  

At first pleasant, but the reminder that the human body inevitably succumbs to the ravages of time and that you’re holding them off better than most for now will come back to you. If the encounter progresses they’ll be expecting you to assign an age to each body part, like an archaeologist. 

‘Wow, you’ve lost weight’  

The ‘wow’ is what does it. Whether amazement that you can be attractive or amazement that one person can lose so much body fat and still be fat, it’s a compliment that keeps on hurting. Might as well go all the way and ask ‘So is this it? Or are you planning to do something about your enormous arse?’ 

‘I love your curves’  

What, all of them? And is this just a general erotic fixation with parabolas or are you specifically keen on a particular curved area, usually the boobs? You do realise pretty much all women are curved, except in Lego? 

‘You’re so brave’  

Unless you’ve just taken a Nazi gun emplacement under heavy fire, this is suspect. Usually delivered without any context before the complimenter turns and walks away, for maximum impact, sparking a fierce bout of over-analysis.