Translate this please!! This guy at work...

k so there is this guy at my job and he doesnt speak english and i dont speak much spanish. well the lady who washes dishes with him keeps saying hey jose dice tu muy bonita. you dont like him?

and i wanna say "i have seen him but i dont know him"

if someone could tell me how to say that cuz she doesnt understand when i say it in english.

'I have seen him but I don't know him'= 'Lo he visto, pero no lo conozco (bien)*'

*bien=well (in case you want to stress the fact u don't really know him).