I never wear sandals (unless I'm at the beach). I'm a sneaker/shoe/boot guy all year round. However, I really couldn't care less what other guys choose to wear. Some guys pull it off fine. Same with girls. I think girls can definitely look hot in flip flops and sandals. Unless of course she's wearing something like...
I don't think anyone should ever wear a sandal that looks like that. Ever. Period. It's just...fugly. If you are a guy and you wear these, that's your choice, but I'm telling you, these are severely hurting your chance of getting laid. Ever. Again. Just warning you.