Susan and Alan - passed the test

Alan touched the shirt to the medallion and felt the familiar tingle. His shoulders dropped in relief.
Being Susan was fun, but he wanted to be himself.
Susan sighed seeing Alan's hair starting to change back.
"Susan, here's the medallion," said Alan as he tossed the medallion to Susan. She caught it, thinking about next steps. She touched the medallion to the G-string, and felt the tingle as she started to get shorter.
"I'll take Scott today to school. It's my turn in the rotation, and now that I'm me again..."
"Sounds good, I'll get to work." The family had a normal morning for the first time in days. Susan dropped off Scott and went to the gym to work out and work.
Alan was leery of the medallion for a few weeks. Susan used it to avoid her period, putting herself at the start of her cycle every week for a few weeks. She took her birth control, just in case. She kept the thong that was during her most fertile unworn, in case she had another chance at some point.
The sex got much better after they changed back. Each one of the couple now knew more about the other person than they dreamed.
After a couple weeks, Susan came up with another plan. One evening after Scott went to bed, she put it into action.
"Alan, honey, can you get me the ibuprofen. It's starting soon I think."
"Been there, I get it. I'll be right back." Alan got up and went to the bathroom. A few moments later, Alan came back with 4 ibuprofen.
"Here, gorgeous," said Alan.
"Thanks. This is terrible."
"I know. It's sucks you have to go through it."
"Alan?"
"Yea, Susan."
"I think I know how I don't have to go through it."
"Oh?"
"...could you be me the few days I have my period? I'll be you and cover you at work. I'll make sure to give you underwear that will make sure YOU don't have to go through it."
"Couldn't you just do something to prevent a period? I know you can't react once it is already here."
"With my birth control, I guess I could predict it..." said Susan.
"See?"
"But would it cause trouble? Being a woman for years on end without a period sounds like a dream, but what if it causes cancer or something? I heard those birth control pills that go for more than 28 days may cause trouble"
"...I guess we don't know."
"I would think being a man would kind "reset" the system, like a period would, without all the pain and bleeding."
"You'd owe me."
"I'd pay you back. When you are me, I'll do the laundry and dishes until we change back."
"And?" asked Alan
"...and drive Scott to school every day."
"Anything else?" asked Alan with a twinkle.
Susan leaned forward and whispered, "and I'd fuck you every night."
"I think we have a deal, " said Alan as he held out his hand. Susan took it and shook.
"Start next month, hon?" asked Susan.
"Sure"