Frances,

There are certain absolutes I have in my criteria for relationships (including friendships).  One of that is that they cannot smoke.  See the CDC’s website for the health dangers of second hand smoke.

https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/health_effects/index.htm

And even third hand smoke is unhealthy:

https://health.clevelandclinic.org/5-things-you-should-know-about-the-risks-of-thirdhand-smoke/

For me, vaping is smoking.  Check out the health issues from that:

Is Vaping Dangerous? What the Science Shows

I agree with anita.  You cannot “force” your boyfriend to quit.  Accept that your boyfriend will not quit and make your decision to leave (or stay) based on that.

Mark