OWW chin up lovey, it's a natural wobble, and I know, you know, that it is, horrible when it happens but you have been amazing in the last couple of weeks. I like snape's idea of the print off for wobbly moments. 
Miranda if it's any comfort, the thing with MrEA staying so often, really materialised because he lives so far away and once he moved jobs, i am actually closer ..... so practically it works for us, if he didn't stay here I would only see him every other weekend. We just sort of fell into it, rather than it being a decision made. I definitely think though that Mr Nice could be staying over at yours. I actually asked my DC's if they would mind if Mr EA slept over, the first time it happened and told them he would be in my bed with me, they were absolutely fine about it and it has never been a problem, they are 14 and 12.
With regard to step families, my STBXH is actually their step dad and despite the fact he turned out to be a complete cheating, deceiving arse, we created a very happy blended family for 10 years, our daughters still refer to each other as sisters and I had my soon to be ex step-daughter staying here with me and my DC's all of last weekend. So it can work and it would have carried on working if he didn't have the desire to stick his knob into someone 20 years younger than him. I suppose what I am saying is, every relationship, every family situation is unique, all have their good and not so good bits. If you are lucky you find something that works for you and the good bits far outweigh the not so good!