I don't know about this one. Anecdotally:
I know a person who, after a break up of a significant relationship, went to all the spots where there were memories that now seemed sad, no-go places, because they were linked to memories of the ex. She went back to all those places and created new memories and worked on that and got those places back. I admire that.
For me, there are songs I simply can't listen to because they're so evocative and I've never bothered trying to make them mine again because there's so much music out there I can easily listen to something else.
My ex ended up with someone who wore the same perfume as me, and I thought at the time that he may have liked the familiarity, he went to someone who was very like me in a lot of ways.
There are a couple of things, "couple speak", that my lovely dream of a partner of nearly 20s years still says, even thought it originated in his previous relationship, and that's never bothered me. That was a good relationship, but incompatible goals, they're still friends, she's really great. I don't mind when he says them.
So, can you make new memories with this scent, or will it forever be linked to sad memories? If so then I guess you could say something, but of course it's his choice.