I am in a quandary

I wrote two posts back that my sister in law was a threat to me and that I didn't trust her intentions. With the support of good friends and advise, that foggy cloud has diminished and I felt a sense of overreaction on my part.

Until this weekend.

I left from work on Friday and didn't return until Monday evening. I spoke with hubby on Sunday night to let him know what time we were leaving the next morning so that he would know when to expect me. His words were this "Don't you EVER leave me alone with THOSE women again!" Who? Well he was referring to my mother in law and sister in law. I told him "I have had to spend plenty of time with your mom and didn't particularly care for it much but I sucked it up and did it anyway!" He then tells me that it wasn't so much his mom as it was sis.

Supposedly mom needed some furniture moved and an airconditioner. Hardly cause for drama but my mother in law always seems to find a way. Sis on the other hand overstepped her bounds. Rough synopsis of the weekend on the farm with Issy gone:

Act I
A comes down and plays video games with M.
Some other friends come to visit with M, one of whom have never seen our chickens.
Sis comes down and stands in the doorway between our kitchen and family room and says nothing.
Our friend that has never seen the chickens gets to tour the coop while A leaves to go to a hockey game.
Sis stays there with M and says nothing.
When said friends whom were looking at the coop comes back, Sis leaves and said friends part ways and leave too.

Act II
Sis comes down the next day and says to M that she is going to the store and would he like her to pick up anything. (Seems innocent so far) He says no thankyou.
Sis comes back from the store and asks is there anything that she can do around the house. (We're testing the line here but so far it still seems okay) M tells her no.
Sis ignores M and starts doing the dishes; all of them and then gets our little boy dressed for bed. (Here is where I start to have a problem)
Sis gets done and asks M if there is anything else she can do around the house so he sarcastically says that she can do the laundry if she wants. She starts going to the laundry room! Hubby then tells her that he's just joking.
Sis proceeds to sit down and tell hubby that before she met her husband that she was a virgin. WHOA!!!!!!!!!! WHAT THE FUCK IS GOING ON HERE?????????????? WHO THE HELL CARES?????????????? The she proceeds to tell M that she was her husbands first.
So hubby asks me "Have you ever said something out of instinct and realized it after it was too late that it was the WRONG thing to say?" He tells her "No you weren't!"
BAM!
Bitch got the smackdown!

Now it's not hubby that I'm worried about, it's my sister in law. My hubby doesn't even know what my first time was and he should know that information; not about sis's. I was advised by my oldest sister in law to confront her. Ask what the hell were her intentions by telling hubby that. Needless to say, I am absolutely furious with her. My aunt even said that it doesn't look good for her to come down every day when I'm not there and I agree with her. Not to mention the fact that I feel completely let down. I've been told not only to keep a close eye on her but to basically be rude to her and tell her that her "services" are no longer necessary. I even had a close friend of mine tell me that she wouldn't be surprised if my mother in law put her up to it since she is upset that she will never have anymore grandchildren with the death of her son.

If I find out that is the case, I have only one piece of advise to give to them: "Both of you bitches better pack a fuckin' lunch".