░P░U░S░S░Y░ ░I░N░ ░B░I░O░
Regardless of whether she is lesbian or bisexual or just curious, I am usually polite and friendly, not wanting to alienate someone who might become a good friend - after all, something attracted them to me. If I nicely and politely turn them down and they persist or become rude, then sometimes it isn't nice.
But I'm flattered, as Lynda3 (above) said. Someone finds you attractive enough to want to be intimate - that's a nice thing.
If it happens in a bar or someplace and I don't know the other woman, then I usually don't get involved, at least not right away. But a few girls I've known for a very long time have made subtle passes at me (and I was shocked but intrigued), and have enjoyed spending intimate time with them.
I relish being approached by a lipstick/chapstick lesbian if she's pretty and sexy, but I usually get approached by bull-dykes, and they scare the crap outta me. I had two of them approach me while I was sitting in our car outside a national park, while David was inside getting supplies at a carry-out. I kept stalling them till he finally came out and rescued me. lol
Seeing that I'm denser than a brick wall at reading if someone is interested in me or not, I would be more than flattered, but then I would probably trip over my words and bungle up any attempt to see if that could turn into a coffee and cake date.
Missed opportunities is my middle name.