Is Dad under any obligation at all to see your son? This is an opportunity for you to teach your son that life is unfair and we don't always get what we want. We can't force other people do anything they don't want to do. And, you might explain to him how it happened that you had sex with a man that was a piece of crap. Dad refusing to see his son is NOT unfair. It simply IS. It is a circumstance beyond the control of either of you. Children need to deal with these circumstances now so that they can deal with it later in life when they find out their control over what other people do is severely limited.