my fiancé wants me to mess with females

My fiancé and I been together over 5 years. When we first me we were out at an after party and I was drunk and kissing a girl in front of him. He assumed that I was into females all along and now he's constantly asking me to find a girl to mess around with while he watches.. this is abnormal to me and makes me feel insecure and awful like I'm not good enough.. anyone else ever have a problem similar to mine???