Yes, invite them, don't lower yourself to their level,
just because they turn their back on him, don't do the same, invite them, its their loss, one day they will regret it, trust me.
know exactly what you're going through, I am an ex jw , moved in with my girlfriend 13 years ago, never looked back, she has been a huge help in my life.
run don't walk (away from the Watchtower)