When I was 19, working my first office job I had to stay late one night to finish some filing. Around 6:45 the HOT cleaner walks in and starts talking to me (as usual, all the guys in the office were mad about this girl)
She was doing a law degree, so working nights cleaning and telling me all about this and that etc, so she grabs my arms through my shirt and was saying shit like "Wow, you must be really strong - do you train etc etc" and I was just getting more and jokey, thinking she's playing me.
She said these exact words, and I still didn't take the bait "Why don't you come in that office over there and show me what you look like with your shirt off"
I replied with.........
Wait for it........
"No hahaha, it'll be too cold in there the AC is on"

This specimen was always "The one that got away" to me 
HA!
I had a similar one, i was wearing my Marine combat boots for some worm i was doing, and we were hanging out in a buddies kitchen when some of his chick friends came over..
Well, this chick asks me if im in the military, i tell her no but i was, she then starts asking what branch, yadda yadda yadda...
Then she goes for it '"ve always liked military boots.... i really like yours, how do i get myself in those boots?"
I no shit look at her like 'wtf kind of retarded question is that?'
And then proceed to tell her "uh, i dont know, you can probably buy them from a mikitary surplus or online from Bates". The look on her face was just total confusion.
So she asks again. "No, i reallly, really like YOUR boots. I can see myself in them. How can i get myself in your boots?"
To which i reply, still completely oblivious
"I can probably pick a pair up from the Naval base for you next time im over there if you really want them that badly."
*legendary facepalm*
The poor girl looked so confused, like she couldnt figure out if she should be sad, or rejected, or upset, or what she should do. Her friend and her kept talking and telling me how they liked my look, etc etc etc, but i was too tired and hungover to care. And then, to add insult to injury, i wound up passing out on my friends couch that night with her friend that rode with her i my lap, and then days later wound up fucking said friend, who was much more aggressive with her sexual advances.
I was completely oblivious.