Here is how I got to it, I never met Wyatt outside of him coming to get the $200. After three times, I think the event I described takes place. I met Wyatt in the park after that event, so do not meet Wyatt in the park or boat and you should get the scene.I think events happen differently for all of us.
When you said "That can happen after a certain event with him", I thought you were referring to the boat scene or their meeting at night in the park.
Before update 3.1, I paid off the $200 debt many times, and the sexual favors option never appeared.
That option only appeared for me after I met Wyatt at the park at night, and even then the option that appeared was directly in the Handjob. The part that mentioned the nipple pinching didn't even happen.
Anyway... I'm going to go back in time and play the whole thing again until that nipple pinching scene that precedes the HJ appears.
He will show up to the door as I described and if you show you care then it happens.