Is my husband trustworthy

Sorry its a long one just to explain the background and my thoughts.I have a question mostly for men but women who have been through same as I have. My husband and I have been together 6 years and married for 2. He lived in a different country and after 6 months of long distance dating I moved to be with him as it was love at first sight and evertyhing felt like soulmates.Just as I moved covid hit and I worked in healthcare. I have moved from home to a place I didnt know anyone but him and was treated badly at work on top of covid. Now years later I realise I was depressed and I was not emotinally available at all. I would just lie on the couch and exist on my days off. My husband however then lost his job and was at home 24/7 and needed more from me. We were living together about 6 months when I found messages on his phone to another girl, flirting, asking her to send some nudes. I confronted him then and broke up with him but I couldnt leave the apartment because I had no close friends to move in with and there was no way to leave the country during the outbreak. So eventually I forgave him but my entire world was shattered then. I really thought he was completely trustworthy and was not capable of such a thing. I forgave him but there always remains that 1% doubt in me that he is capable of something like that. Fast forward to now. We were drinking and playing truth or dare. He said that he would like our sex life to be more adventorous and that he would be open to a threesome male or female. I found that as a huge red flag since I am very vanilla and personally I feel disgusted to even think of another man kissing me. To me this feels like in 20 years when he hits mid life crisis he might just cheat on me then because he will always feel like there is something missing. Am I overreacting here or are my doubts justified? He is saying im overreacting and him texting another girl and asking for nudes wasnt cheating and he would never cheat on me. Im interested especially from a mans point of view. If you were my husband should I trust you?