When should be concerned that you haven't been introduced to the man you're dating son?

This is my first time dating someone with a kid (5yr old) and we've been talking for about 5 months now and I've never meet his son. I've attempted to put dates together that would involve his son but he's always had some excuse or just ignores the thought.

Does not meeting his son draw a conclusion as to how he feels about me? What if I don't like his son? You would think he would introduce us from the beginning to make sure we could all get along. Any parents out there can shed light on if this is normal or anyone who has dated someone with a kid and enlighten me with their experience?

Thanks,

Deep