Making it up as I go along

we had a family over for dinner tonight--which we rarely do. they are a family of five but tonight were only a family of three--they only brought their little boy austin who is 5 because his big sisters had other plans. sadie was so excited --austin's mom--taught sadie's class in preschool last year and sadie adores her. dan and I love entertaining--it gives me a chance to dig through recipes and cook a meal I would otherwise not make for my family.
I made chicken marsala, spinach salad, green beans with honey and butter, and spinach and artichoke dip.
sadie, austin, and laken seemed to be having a fabulous time.... we only had a few incidents where the kids weren't getting along.
later when we were putting the kids to bed. dan asked sadie if she had fun with austin--she stated "no" he was mean and made me pull my pants down.--whhaaatt?? I called austin's mommy to make her aware--I guess he was curious and sadie didn't know what else to do, innocent yet really upsetting to me as a mom. I love my babies and it is amazing the emotions and feeling that can arise from an incident like this. I tried to explain to sadie ( who is 4) that her body is hers and no one can make her do anything with it that she doesn't want to.