When is the right time to introduce a new partner to your kid?

I took a break from dating because I either chose wrong and they caused me or my children trauma or I chose right and decided to destroy it. I have 3 kids. They all have different dads. My middle son's dad was a great man but because I self destructed I cheated on him with my youngest kids dad who went on to abuse me. I made many mistakes. One of my past partners molested one of my boys and the last one before I gave up dating threw my daughter down the stairs. I took a break. All my kids are teens now(17, 15, 13). I haven't dated in 2 years. I worked on myself. My kids are in therapy to work through their trauma. My 15 year old is in EMDR therapy to work on his CPTSD. I've taken the right steps. They are not happy I got back on tinder but I promised them this time would be different. I will never allow anyone to hurt them again and I won't self sabotage anymore. I'm talking to a guy. We've been seeing each other for 2 months. I feel like he's the one. He's perfect. I'm not sabotaging it. When should I introduce him to my kids?