If you dreamed of being a voyeur (secretly watching someone else, particularly if they were making out or having sex), this suggests that you are afraid of your own desires and fantasies. You could also afraid of getting close to some relationship or situation in your waking life.
Alternately, you might be a nosy person who is too involved in other people’s dramas.
If you dreamed of someone else watching you though, you may be feeling guilty about something. Be careful not to act too impulsively.