Hello greenplants: I noticed this is your first post here on PC. So... welcome to PsychCentral! I hope you find the time you spend here to be of benefit.
I read through the previous replies you've received to your post. And each member made some excellent points. I think the two things I'd like to key in on are the resentment you're feeling and the fact that, when you mention your concern to him, your bf scoffs at you. Neither of these, it seems to me, are good signs. I do think you are correct not to confront your bf with your suspicion he may still be subconsciously in love with his ex. While you may feel this is a possibility (& it could be) tossing that in his face, so to speak, would I suspect cause a real rift in your budding relationship.On the other hand, the resentment that is building within you is also not going to do your relationship any good.
Off-hand I can't think of any particularly creative solutions to this problem. Perhaps, as I think has already been suggested, this is simply a case of too much closeness too soon. Maybe the two of you just need to back off a bit & let things develop more gradually... if they will...
The other thing that occurs to me, though, is that there is a sense in which this becomes a matter of respect & personal boundaries. If, when you express your feelings to your bf he scoffs, he's disrespecting you, denigrating your feelings & transgressing what should be your personal boundaries... in my opinion. Unfortunately, as I wrote above, I don't know of any way to really change this. Ultimately, you only have control over yourself. You can't mold your bf into the person you want him to be. So, from that perspective, perhaps this is a sign this relationship may not be the one for you?
Here are links to a selection of articles, from PsychCentral's archives, that hopefully may provide you with some additional insight into your situation:
What Are Personal Boundaries? How Do I Get Some?
Why Healthy Relationships Always Have Boundaries & How to Set Boundaries in Yours
Fall Down; Get Up; Fall Down; Get Up | Building Relationship Skills
3 Keys to a Strong Relationship
7 Pointers for Couples to Prevent & Resolve Misunderstandings
https://psychcentral.com/lib/dont-as...rase-the-past/
https://psychcentral.com/blog/when-y...e-a-loved-one/
My best wishes to you both...
https://psychcentral.com/blog/5-warn...relationships/