Is one of the morning Monday activities on wake-up. If you denied her the first time at the livingroom, thats it, you wont be able to go.
I visited the yacht 3 times before, but on the 4th Monday, the button disappeared and the quest remained
On Monday, I get the Studio Relax Work and Gym buttons
Did you get to have sex with her at the Yatch, if you fully deny her there the outcome will be same as you not accepting the invitation.
