Hard for me to say without knowing at what point you're deviating from the path, but I can say you don't need Ash to be a bad girl to have the threesome.Yeah managed to get the first two, what are all the requirements for getting the Jasmin/Ashley/Jack threesome though? Already tried being Jack's girlfriend and that didn't work. I guess maybe I didn't have enough "bad" points?
I'm gonna be making a big guess here, but after taking a quick look at the code, I think the problem is that you are commiting to your relationship with Jack, if you choose to commit to your relationship with Jack, you can't access the threesome content with Jasmin.
There are 2 ways around this as far as I can see, first you can just not be in a relationship at all, stay single but be having sex with Jack, this should give you the option for the threesome.
Second, if you want to be Jack's girlfriend, then you need to not have an orgy with Tyrone's friends after the poolparty nor become Tyrone's muse, if you do either of those you will be forced to choose between either commiting to your relationship with Jack or breaking up with him. After that, if you have been having sex with other people while dating Jack, you will be given a choice between commiting to your relationship with Jack or to keep on cheating, you must choose "keep on cheating". This should let you have the threesome with Jasmin.