It's not surprising your ex took it very badly , is it? Because she#s the person left dealing with the fallout and damage you do to your child.
This is your one=off chance to tell him the truth, because if you don't he will surely one day hear from someone else in uglier terms that you're a crook who did time. He needs to know he can trust you, so don't lie to him. Keep it straight. Don't just say you were naughty, because little boys are naughty too. Don't make him worry a police man with get cross with him and send him to jail.
Whatever your crime was, put it in simple in terms a child can understand. You stole somebody's car/you got in a fight and hurt someone/ drug crime/. It was wrong,it was stupid, you shouldn't have done it/.
Then you tell him that because you are a grown up who did something wrong you are being sent to prison and will be locked up. for a while.. one day you will be let out. It's sad you won't be able to see him, but you will write him letters and send a birthday card etc.
If he can trust you not to lie, cheat, let him down, that's a start for a future relationship . Keeping in touch (even if its one-sided, all by you) is the way to go. Do not write letters about "poor tragic lonely me ", or maudlin promises to be a better dad; no sermons. Keep it light, talk about films he might have seen, football, TV, or that funny dog. Can you take a book of childrens jokes with you?
Don't tell him about your dads past. Don't ever let him think that having a dad who went to prison means the son will end up the same way. Above all, don't come out of prison in a worse state than you went in. Keep your eyes fixed on being a better version of you when you can see him again.
That's the end of my sermon :-)</div></div>
Lots of good advice there. Well I have told him the truth now and will deal with that. I really couldn't have just disappeared on him but could have come up with a story.
Never thought about what you said about writing to him and to talk about all the things he is interested in and not talking about serious stuff.
I've never told my son about my Dad being in prison. He hasn't been around since my son was born so no need to mention it before. Yeah I wouldn't want him to be thinking that me ending up in prison like my Dad could happen to him. I know he's only 7 but he is really great kid and couldnt see it happening any way.