Betraying nervousness can be done in a variety of ways, such as pacing, fidgeting, and tensing up. Pacing is the act of walking back and forth in an agitated manner, while fidgeting is the act of making small, repetitive movements with one's hands or feet. Tensing up is the act of tightening one's muscles in response to stress or anxiety. All of these behaviors are signs that someone is feeling nervous or anxious.