Rollback to the coffeeshop scene and make sure that you gave the correct answers, if so, MC will promise to try yo get an invitation from Marcie and he can take Megan with him. A day later or so after you watch Megan and Karla having sex at the clinic, Megan will come talk to you to check how things are going with the invitation (this means you're on the right track with her). Collect the mushrooms from Alicia at the hotel, etc. Then on saturday when you're watching Megan picking clothes for the party on the telescope, there'll be a option for you to invite Megan (call her while voyeuring) or dump her and go with Alicia instead. I think that's it.
