I'd also reconsider what your values are and how they may be genuinely problematic for your relationship with the teen.

Tough Love -so far as I understand- places the entire onus on the young/badly behaving person, assuming that prevailing middle-class nice attitudes about behaviour and conduct are RIGHT full stop!

I learned from my delinquent adult, that you have to accept that other people don't always hold identicle attitudes about right behaviour to you, and furthermore they have a right to do so too.

What they don't have the right to do however, is to screw you over and fuck-up your life. So basic self preservation is where I would say "No further!" - I think that's a basic euphemism for "tough love" too.