The WT says that you trigger the Goodbye Eric event by interrupting Lisa and him. But I was also told that you trigger it by drugging him constantly (which also was my way to do it, I was just not sure, that this was the trigger).
In the original version it also would only happen if you had 600$ cash, I don't know if that's important in the remake.
Once it happens, you need to have Alice sleep naked when Eric visits next time.
Aparently, if at that point she does not do it, you will get a 1-choice option when she smokes, so you can't miss it. I can't confirm that, I had her sleep naked anyway.
Remember, if she promises to sleep naked but won't do so, you can place a spider in her bed for motivation.