seek, I dont think we are talking about dating them or living with them. In a one time thing I think twins are better, unless of course the mum is super hot. If you look at the reality of the situation you probably have a 40yr old mother, and her 20yr old daughter.. the 20 yr old is hot, and the mother is not. If they're acting together with you, then thats sick. If its one at a time its not so bad. Same goes for the twins. Its rather sick on their part to have sex with the same person at the same time. At least with twins your gettin it on with two younger girls, instead of an old lady.
Mums and sisters alike have emotions so that is irrelevant.