T2I auto setting issues

This is my first post here, I appologize in advance if this has been discussed but I am not able to find an answer to this question. I do not have any trouble taking photos with my T2i using the kit 18-55 lens in auto or manual mode. The issue is when I hand off the camera to strangers and ask that they photograph myself and my fiance. For some reaosn, it wont shoot in auto mode in dark situations at all. If I take the camera and point it at the same place in manual mode, I am able to take the shot. Any advise offered would be appreciated. Thank you.