Do guys like girls in thongs, or is it considered "slutty"?

Lol, i may hook up with this guy soon, and I tend to prefer thongs, but some of my girl friends tease me about it because they hate thongs. I mean, I don't wear them ALL the time, but i just think they are more comfortable. But would a guy think my butt is too bare if he saw me with one on? I do have a nice butt...but do you think he'd prefer me to wear boy shorts or what? or do guys like thongs? help!