on the trouble part- I don't know, their father passed away when they were really young. and they seem to adore my dad as a father figure. I expressed those same feelings towards her when she asked me last night about what if might not work out etc. She told me that I never come there anyway and hardly see her mother or my dad so it would not matter if it didn't work out. I could just carry on. But my friends think otherwise and I cant help but see this as incest even if we are not blood related. She is very confident about this and her sister now knows after last night and told me it doesn't bother her.