How to mount a horse with two people?

I'm writing a story. A man is riding a horse into town and wants to give a woman he meets on the side of the road a ride. He climbs down, they chat a bit, then he wants to help her mount the horse. The problem is I want the woman to be sitting behind him, not in front of him. How can this be done actually? I tried to picture it in my head, but the details just don't work. Does he get on first and hoist her up (which would seem awkward now that i think about it), or does he lift her up on the horse and then gets on himself. if it is the latter, the woman will be in front, and that is not what i want. I've looked through some movies, and this movement is never really done on camera. They always cut to them already on the horse...Anybody here a mounting expert?