Iqqi, props for having the courage to post your situation here.
First off, life is about taking chances, going for it. I think that's what Joekerr's getting at, and I agree.
It's about being different, if 99% of women are playing the flirty covert 'game', if you are in the 1%, that actually be overt, you will stand out.
You probably could have closed the deal by buying him a drink, like joekerr suggested....because it's different!! 99% of women would do the same thing as you did, and then analyze the results later, and dream of next opportunity...
When guys buy flowers, etc..remember that he's doing what 99% of guys do, trying to buy her affection, that's why by not doing that, and focus on 'game' for a guy, put's the guy in the 1% different catagory.
As a guy, if I'm interested in a gal, nothing personally is better, than for her to give me a blatant green light..something that I will not misinterpret.
Also, on a side note, consider you may increased your friend's attaction for him as well..by giving him value. You created competition in her mind. Therefore, she may be the one who took a chance, and was overt.