The last couple of times I tried in the bath were no goes.
Actually, I have a theory (which seems kind of a no-brainer now).
I think it has more to do with mood than anything. I think usually when I try it in the shower it's sort of an obligatory wank, if that makes sense (and usually in the morning). I'm not really into it. Not really 'worked up' so to speak. I'm just not able to work myself up to it in the shower (although I can get an erection). Today was a different story. So maybe that's the problem. Maybe if I only tried it in the shower when I was totally worked up, I would have 100% success...no?