
Yes to separating them - as suggested all too often males who live with a bitch and used to being put in their place, are reluctant to mate with them.
Do you have an experienced breeder-friend you can call on to help you mate your two? As my main breed can be very difficult to mate, I had a good friend who was very experienced with my breed (she could mate chairs to tables!!) and for a small percentage of a stud fee, I'd call on her! Far better than messing around and getting nowhere (especially with a visiting bitch).
On the other hand if you guide him, regardless of his penis being exposed beforehand or not, you may find he will penetrate just fine, if in the right place!
I've not known toy poodles to be reluctant in this area