If your transmitter emits enough power to be heard more than a few meters away, the likely result will be destruction of components in the receiver and possibly in the transmitter as well.
Receivers are designed to amplify, detect, and decode signals in the range of a few to a few tens of microvolts; transmitters as weak as a few watts will put tens of volts of RF onto their antenna. The latter signal, applied to the receiver's components, will at a minimum overpower and desensitize the receiver, resulting in no reception at all. It's very likely that this level of power will damage components (transistors or integrated circuits) in the receiver RF amplifier or detector stages.
Further, the receiver (at least after components start to burn) will appear as a grossly mismatched impedance to the transmitter, and the reflected power from that mismatch might well damage the final amplifier stage in the transmitter (burn out transistors, pop capacitors, etc.).