Yes exactly, and the screen chemistry between GDL and JB is palpable, I still remember so well the first time I saw Ianto, in the first ep, and the look they exchanged with the little flirt about the suit. I thought two things, chemistry, and there's the UST. I don't think you can buy that sort of chemistry, it is a natural thing, combined with good acting of course in order to work. They have developed a way of being with each other in their body language which is very nice. It was even there a couple of times in DW.

Yes EM can be very shouty and irritating, so he then cranks it up, and their body language gets all gesticulating and then the eyes start. That's when panto comes in.