Hiya Roughquest, blimey you do move quickly! Well, I think you should wear whatever jewellery you like, but I do think wearing your engagement ring when you are living with someone new, who you say you love is wrong. I am an insecure person, so telling it from that point of view maybe. But that aside, I do think its not right. I could be sending out signals to your partner that you still have feelings for your ex husband.
Tend to have a habit of talking about my ex on posts (sorry all) but when I first got together with my ex, I used to wear lots of rings. He told me that it made me look aggressive! (they were lovely silver rings) so I ended up not wearing any. Apart from the old fashioned one he brought me.
Sorry that story had nothing to do with you, but I started questioning the way I dressed and everything, so think he was just as insecure, though he never admitted to it. Sounds like he a bit like that.
I hope you managed to talk things through with him and have got things sorted.... let us know.....good luck xx