This type of question arises from time to time and I do find some of the responses strange. For me it's simple. If your friend wants to see what an F apartment is like then either:
- pay for an F apartment, or
- look on youTube
I don't see how anyone who pays for a J ticket and expect to sample the perks of F (even for a short period). If the op and his friend want to be together then the op goes to J.