Bolt out of the blue

Well having announced to the family that yet again I failed to get pregnant, by sister comes up with an idea......she'll have a child for me.  She'll be a surrogate using Peter's sperm i.e. Peter and my sister to have children together and I raise them.

Not sure I can cope with that idea.  I am able to cep with the idea of adopting and the child not being genetically related to either of us, but my sister and my partner....too much for me to cope with right now.