Well again I can kind of relate. I am not 'aggressive' in starting anything unless I really want to sleep with a girl or really want to have a relationship with her. If I like a girl, could potentially see something happening, but am not too bothered then I'll quite happily hang out with her. Quite often that then makes me like her more and puts her into one of the groups of gals I might pursue more proactively... which I then do. I must say though, I have learnt a lot about girls from women I've not had a relationship with.
There is a difference between that and what your guy said though. And I must say, I do think my way of doing it is healthier. He is operating from a position of fear and insecurity and, basically, lies. He really likes these girls, but doesn't tell them and friends is a second best whilst he is actually angry and frustrated and resentful. His ideas about commitment are also all over the place.
So yeah, again, it'd be interesting to know how he acts/acted around you?