Hi guys

So, I remember one of my favorite movie scenes that made me laugh a lot !
the scene was " a guy and a girl in a bus or train I'm not sure, they saw a woman and they thought that she is pregnant, they came closer to her to have a look and hear the baby's movement, the guy started it then he asked the girl to do the same. finally the woman said I'M NOT PREGNANT !!

please help me in finding this movie !
Thank you