Oh you mean you can still have the MFM talk AND the trinity if Lena has cheated ? I didn't realise that. I'll give it a try. One more occasion for EK to be frustrating. I was already pissed by the fact you could not offer a 3some with Louise to Ian unless you had slept with her first, so now....
Yeah. My Lena only slept with Louise to achieve Open Relationship status too. I had no interest other than getting that Open path, with the ILL threesome a nice bonus surprise.
I'm not sure if allowing the Trinity at the same time as the MFM convo
only when Lena has cheated is a design bug or intentional on the part of Eva though. Might be due to a future plot point, but the inconsistency just doesn't make any sense.
If you do a playthrough for this, keep in mind it might depend on which dick Lena cheats with. She let Marcel Muh Dick her throat in chapter 9, but never messed around with any other guys aside from Ian. You may or may not be blocked from either the trinity (more likely) or the MFM talk if she's banging Axel.
In my playthroughs, you can also have Lena decide mentally at her parent's house in Chapter 12 to stop cheating or to continue cheating. Both resulted in the Trinity AND the MFM convo on that save's playthrough. As long as she choked on some non-Ian dick before that chapter, selected MFM as her fantasy in Chapter (9?, 10?) & was also on the Trinity route.