it'll (all) end in tears
Something is doomed to fail and cause a lot of heartache to everyone involved. I just don't think your personalities are a good match. I'm afraid it'll all end in tears. Everyone knew that their business venture would end in tears.
it'll end in tears
When people say it'll end in tears, they mean that they think a situation will end badly, with people being upset. Boris got himself involved in a relationship with a foreigner that was destined to end in tears. Markets are not stable, and for many companies and investors, it could well end in tears.