The bridge is an intercourse position in which the guy lies on his side and the girl on her back.
If the guy leads the movements, he moves his pelvis back and forth, while the girl lies quietly. If she does the moving, she can push her buttocks back and forth against his pelvis, thus moving the penis back and forth. It’s rather easy for both to move in this position but you have to experiment to find the right movement.
It’s easy to keep going because this position doesn’t take much effort.
The girl has both hands free to caress her lover or to stimulate her breasts and/or clitoris. He also has one hand free to do whatever.
In this position it is easy to use a vibrator.
A drawback of this position for the girl is that it stimulates the side of the vagina, which is for many girls less exciting than stimulation of the front or back of the vagina. A drawback for the guy is that the penis can easily slip out, which calls for short thrusting movements. As a consequence the glans is not strongly stimulated.