How do i have sex on the bed and make her come

Step one, find a girl who is willing to go in bed with you
Step two, step one is impossible for you so give up.

If it's a smaller child or infant, place one on the middle of the chest and on the child's back. (if it is a bigger child with enough room for two, place one on the upper right/your left of the chest, and one on the lower left/your right) the pads should never touch each other.