Every time I said anything to my ex partner that he interpreted as confrontational (and these were truly dreadful things such as "can you please move your hot mug over to a coaster so it doesn't burn the table") he would say that he would move out if that's what I wanted. It was manipulative behaviour in the extreme and very childish. Eventually I took him up on his suggestion and agreed that maybe it would be best if he did move out. He was shocked to the core and immediately turned into "Mr perfect, loving, caring man", but it was all too late and I stood my ground. It took a further 2 weeks for him to go as he was relying on me changing my mind, but once he was finally out of my life I felt a huge weight off my shoulders and have never regretted my decision.
By the way, you don't need a lock smith to change locks on modern doors and charge you a fortune. Just search "how to change a lock on a UPVC door" and follow the simple instructions. I bought new locks just before he left, so was able to change them as soon as he left which made me feel so much more secure.