Unfortnately this has happened to me as well. My now EX-husband was very close with his sister, he would constantly talk about her (which is okay, i mean he was proud of her) when i was first dating him, but i just sort of brushed that off. When i actually saw how they interacted (hug eachother everytime they came close, caressing eachothers arms, tickling) i was freaked out. he was military, so when we (his sis and i) would pick him up from the airport, she would run past me to him and jump on him and wrap her legs around him right at the gate. and he thought that was completely normal! i thought he would realize his boundaries with her when he married me, but it only became worse. Both my ex and his sis continued on flirting with eachother and they basically acted like the married couple while i was the third wheel, they even made decisions (WITH OUR MARRIAGE) together and then would talk to me about them after they had already decided what to do! i was kind to her the whole time i knew her, but i told him it had to stop. (even though he said it would, it never did). this along with other problems, led me to divorce my ex. From my experience, i say run the other way and FAST!

Prudy, you have no business giving advice! You're more incompetent than Dr. Phil! This woman needs to call the whole thing off! Her fiancee is obviously too "close" to his sister and marriage will only ruin her life if not her own reputation! And your obvious attempt to normalize incestuous relationships by comparing them to Greek mythology is absolutely disgusting! There's this thing called morals, lady! Get some!!!!

I waited until I was almost 26 to get married, and I still didn't pay attention to little "checks" that I'd occasionally get while my husband and I were dating/engaged. It didn't turn out to be as bad as these two that are mentioned, but bad enough. Those little checks that you get before you marry a person, pay attention to them! Don't brush them off. Those oversights become alot bigger after you marry and have children together.

I agree with kdrizzle, run the other way and FAST!

What little checks in the story are you referring to?