I'm not cool with him donating sperm to any woman at all... despite the fact I would donate my eggs. For me, his sperm is his sole contribution to a pregnancy. My contribution is both eggs and the use of my uterus for 9 months... so I feel that's different.
Still, I'd never donate them to an ex. It's too messy. It's too icky. It's too hard to view that as a rational, logical person without jealousy and icky emotions making it tough to get on with.
Ain't no way in hell I'd be okay with it. At all.