I tried to flirt with an ISFP once at work. After six months we would actually smile and nod at each other in the hallways. We still do this and sometimes he checks out my legs.
I just gave up after awhile. He seems very nice but we seem to be living in parellel universes. He plays in a band and seems really cool but it's like wires that never really cross. We just dont have much to talk about, and he never talks much anyways.