I (M28) slept with my Wife’s (28) younger sister (f23) at their brother’s wedding

I could give more backstory, but suffice it to say I used to be a couples dance instructor in 2010, and had taught both sisters to dance.

Almost a year ago, my wife Selah and I went to a fundraiser, and had Noa, her little sister babysit our 2 boys. My wife is really pretty. Taller then average, but not much. Auburn hair and brown eyes. She’s around 120 pounds, and has small but pert breasts. I just wanted to get that out there.

I was leaving the fundraiser early, to catch a bit of a concert a High School friends band was doing. I drove home, which Noa was expecting. I was just there to change, but we always had had really good chemistry, so we wound up talking for awhile. Back when I had been a dance instructor, Noa had a big crush on me. Every since then, we’ve always enjoyed being just a little flirty.