That is interesting! This seems to be an in-build fork and acceleration based on how good or bad your relations with Jamal are. Because if you are on good terms with him, there are small, but feelable differences in the lead to and during the birthday event. For example, if you are on good terms and lean towards romance and/or fun sharing, your wife telling you that the party is at Jamal´s flat, you react with an relaxed OK. If you are on good terms with Jamal, but you lean towards (unwilling) cucking with e.g. "Friends with benefits" active, then you react less cool and not really happy.Okay I got curious and checked out what Azerak was saying. There's definitely something bizarre going on with that party. I turned sharing on, told wifey about sharing, sabotaged Jamal at every choice and didn't even enable snooping. As far as I can tell if Jamal and the MC aren't on good terms wifey unavoidable fucks Jamal on that scene and MC definitely isn't happy about it. That's with 0 snoop, 0 relationship progress with Jamal, no drug haze perk and 1 Jamal point which is as low as it goes and max love points.
There are also some differences in how the birthday plays out if you are on bad terms with Jamal.
I estimate 3Diddlyf95zone made a design decision to keep the side branches corralled in, based on your relations with the rival/fuckbuddy. I think he went with the idea that at this time in the game you either develop towards good or bad relations respectively and choose accordingly.
The paths and subpath differences function very well, if you consistently choose either good or bad relations with Jamal or at least switched early on after first or second time this specific choice comes up.
Yes, it is an option to choose antagonistic at the birthday party even if you were on good terms with him before, but it does not really make much sense to do so at this point anymore. If you choose good relations in the events before the birthday party, you can see each time you do an easing of tension and becoming step by step more chummy.
Likewise if you choose antagonistic, each time you do behaviour and sympathy plummet more and more to rock bottom.