Twins playing a trick
Been thinking a lot lately about being married or dating a twin link identical twins so much so that you can really only tell them apart but the way they dress and talk. But if she's in bed asleep that doesn't leave a lot of ways to tell.
I'm thinking maybe the sister is horny and doesn't want a one night stand and has no steady bf. So her sister (my wife) reveals to her that she has a sleep play kink and it's normal for me to come in and fuck her while she sleeps. My wife explains she doesn't mind lending her my cock but felt it would be best if I didn't know it was happening.
So she tells her sister just to lie on her bed and wait for her husband to get home and just pretend to be asleep.