Chasing happiness

Sooo, I want to move in with my ex girlfriend (from 8 years ago), but my friends don’t really approve of her nor do they really understand the type of relationship we had/have now. Now, I know what I want, and if it doesn’t work out I have a back up plan. However, I have 3 ways of going forward that come to mind. 1. I leave, disappear without a trace, just go. 2. I lie and tell them I’m moving in with someone else (not my gf). 3. I tell them the truth, and face whatever consequences that comes with. Which one should I do? Yeah I’m already under the impression many will say I’m a bad friend but there’s a lot of mental reasons for this move