Your friends gave you very bad advice. Every relationship talk is another nail in the coffin.
You want him to think you’re happy he’s leaving. Like BL42 said, pack his stuff in boxes, leave it on the porch and wish him well with a smile on your face.
Every time you have a relationship talk he a) loses respect for you because you’re letting him treat you like crap b) knows his backup plan is rock solid and so he knows he can pursue things further with OW
