That's tough. I think they will need to realise that the commitment to having seed funding and a co-founder are not the same as a lifestyle business - especially when they do not have funds of their own to fall back on and revenue is not presently hitting the numbers that would be needed.

Even a lifestyle business requires more than just 'coding'. That person at least is likely to have an unpleasant awakening. I just hope it doesn't hurt either of you too much