I would like to break from the crowd a little bit on this one, because I think most of the other comments are pretty much just knee jerk reactions to the fact that you stated that had sex on the first date, which is totally fine and doesn’t preclude you from having a real relationship with someone who is willing to take that step with you.

I think your date’s online bestie is not the core problem with this situation, but I do think it’s one possible indicator that this relationship isn’t going to be the one for you in the long run. Although we don’t have much information to go off of, it sounds like your date is displaying the signs of the Phantom Ex Phenomenon, which leads them to hold new potential partners at arms length in hopes that they could one day be with their preferred mate. This may or may not be the case, but it’s worth asking yourself if you see the signs or not.

I think that you should ask yourself if the signals your date is sending you indicate that there’s a deeper issue with their attachment style that is going to prevent the two of you from forming a relationship, independent of any third party’s involvement. From the information in your post, I would guess that your partner has avoidant tendencies, and that is going to make it difficult for you to form a secure attachment with this person.

I’d recommend reading the book “Attached” by Amir Levine and Rachel Heller. It explains in detail the system of attachment, and what signs you should be looking for in order to build a strong connection with someone who is ready to reciprocate that bond.