I can't switch between sims

This is a major problem. Whenever I asked my sim's boyfriend/baby-daddy to move in with her I am unable to switch back and forth between them properly. When he moves in, it automatically switches to him as the sim being controlled but when I click on his girlfriend/my original sim, only the plumbob indicates that I've switched. The main picture on the console thing still shows the boyfriend and the thumbnails of the two sims is lit up as if both sims are selected.

Does anyone know how I can fix this? Or need further clarification? I'm asking here first in case the answer is simple, but if I can't get something to work I'll contact EA for more help.

PLEASE HELP!!!!