There were even more categories, but you were too confused to keep on reading, you just clicked on the first one you understood, "Partial fusion", you read the description, and it meant that you were only going to be a part of him for a chosen duration.
You knew exactly what part of him you wanted to be : his pits ! This thought made you incredibly aroused, you kept on filling the form even faster, you were so impatient.
The program then asked you what part do you want to become, for how long, to you want to be sentient, do you wanna keep your senses, etc…
You filled everything, and finally you read it one last time to make sure it would be perfect.
The change would last for one week, you would become Alan's right pit, you would hear, smell, feel and taste everything but could not see, Alan would be unbeknownst of what you did, and of course you couldn't communicate with Alan in any way. That's exactly what you wanted ! You clicked on the big, bright-red "Transform" button.