Are you completely sure that it can't be salvaged? Have you talked to your co-founder about the sort of work you were expecting? If you've not called them on it previously, they're probably assuming everything is fine. A gentle prod may be all it needs.
If you really must break up (I feel like I'm giving marriage counselling here...) I'm sure you can do it without being an asshole, something along the lines of the letter you've posted here would be fine - to the point and no personal attacks.
As for your partner having your IP now, well that's probably too late now - horse, stable door, bolted etc. I think the best you can manage is to perhaps come up with some sort of agreement (possibly consult a legal-document-writing-type-person to get this in writing) so that you both agree not to sue each other in the event that either one of you does well with it and the other gets sue happy.
Yes, it'll set you back and you'll have to find someone else which is why I suggest you try and work it out first. Otherwise, I'm sure there web sites where you can advertise for this sort of thing ;-)
Failing all of this and you decide to ignore my advice, I would suggest a fight to the death involving pistols at dawn or something.
"Are you completely sure that it can't be salvaged? Have you talked to your co-founder about the sort of work you were expecting? If you've not called them on it previously, they're probably assuming everything is fine. A gentle prod may be all it needs."
It's too early to treat it this way. This is a total Splitsville situation.
I couldn't agree more - it's all too easy to construct your own interpretation of what's happening and then convince yourself it's the absolute truth. Before you split you need to talk to your co-founder and at least give him a chance to put his side of the story forward.
If you really must break up (I feel like I'm giving marriage counselling here...) I'm sure you can do it without being an asshole, something along the lines of the letter you've posted here would be fine - to the point and no personal attacks.
As for your partner having your IP now, well that's probably too late now - horse, stable door, bolted etc. I think the best you can manage is to perhaps come up with some sort of agreement (possibly consult a legal-document-writing-type-person to get this in writing) so that you both agree not to sue each other in the event that either one of you does well with it and the other gets sue happy.
Yes, it'll set you back and you'll have to find someone else which is why I suggest you try and work it out first. Otherwise, I'm sure there web sites where you can advertise for this sort of thing ;-)
Failing all of this and you decide to ignore my advice, I would suggest a fight to the death involving pistols at dawn or something.