Yes, I expect he is playing a game with me so I drop my break clause. I could, I suppose. Or I could keep both in, retaining my right to break the lease: he is very unlikely to use his, since he doesn't want another void period as he's just had one.
Then again, the thought of living with a break clause hanging over me is bad. I'd be homeless, whereas his risk is just of one of his numerous investments having a slightly lower return. Wow the tenant is actually better protected in America than here. I should have stayed there..
Thanks for the advice.