My sister and I want to disclose our relationship to our family. Any advice on the best way?

Hello. Yes, this is real. And yes, I'm obviously using a throw away account to protect us.

My sister and I have been "together" since high school. It's both physical and emotional. I'm 18 months older. We both stayed local for college so we could see each other, and after graduation she moved in with me "to save money." She is the love of my life, my best friend, and the only person I can imagine spending the rest of my life with. She feels the same as well.

In fact, the only thing that is not going well is our relationship with our family. They all thought it was so cute I took my little sister to prom, or that she followed in her big bro's footsteps going to the same school and getting the (almost) same degree. When she moved in after college it didn't sit well with our Dad. Mom stuck to the old line she always uses, "they've always been inseparable." Or her classic "2 peas from a pod." Mom always seems to defend us from criticism. We also have an older sister (she's 5 years older) who definitely suspects things are going on. She makes comments all the time at family functions. Her little digs are subtle but constant and at a recent get together caused our mom to retreat to the kitchen and cry.

We think our mom knows. I even think she's ok with it all things considered. We are happy, healthy, and not alone. We don't know about our sister and Dad. We wouldn't tell anyone else in the family.

So what advice does Reddit have? We aren't looking to do this tomorrow. We have a few irons in the fire. Possibly seeking advice from a therapist. We'd discussed Thanksgiving as a possible time to let everyone know. Our sister will be there, but her husband will be traveling for business so it presents a good scenario for us we think.

Finally, I know some will want to shit on us for the relationship. To them I say this, we have been together almost 20 years now. Most relationships don't last a fraction of that. We love each other VERY much, but we are also very realistic. We know there is no marriage or children this route. We've discussed all that and we want to be together. Thank you for taking the time to read this. Technically, you are the first to know now. I'm shaking a little as i'm about to hit "POST".