You feed, exercise, play with, train, and have Teddy with you far more than your boyfriend does. It is only natural for him to look to you for everything. Your boyfriend should continue to do as he is doing plus maybe take him walking a bit - just the two of them. Give it time and hopefully Teddy will discover that he has another great person in his life and love him also.
I'm sure Pucks104 is right, Madelon; Teddy isn't NOT liking Paul, he's liking you more and waiting for you. That he sits on Paul's lap says a lot - neither of my dogs is much interested in anyone's lap, including mine!
The whole 'pack leader' thing is now hugely contested; it's still controversial, mainly because some people cling to disproved beliefs, but the massive accumulated evidence based upon research into what wolves REALLY do (as opposed to our touchy-feely sense of what we THINK they do) says that the whole 'Alpha' leader idea is misplaced and unhelpful. There is NO alpha wolf. There is a breeding pair who are the dominants in a wolf pack. They never go first along a path, for example; they always allow a subordinate to go first in case there is danger. They never eat first for the same reason. There IS an omega wolf, one who appeases, breaks up fights and generally keeps the calm; this wolf could once have been half of the breeding pair, or could become so. He is by no means an underling, he choses his role, does it to the best of his ability and is hugely important for the stability of the pack. All these discoveries have implications, obviously, for domestic dogs and how we interact with them. Read "The Truth about Wolves and Dogs" if you are interested (by Toni Shelbourne); it's fascinating, and also full of training tips based on this new research (she works predominantly with wolves, but owns dogs).
Meantime, it sounds to me as if you and Paul are doing just fine. You've only had Teddy for a relatively short time; he has had another life before you took him on, with relationships that you can presumably only guess at. I've had my Coton, Tycho for all of his 7 years, and he still, given the choice, would rather be with me than with my husband, despite the fact that my husband is the one who walks him mostly, at least of late while I've been training Cuba (my Havanese 11 month old). Paul might just have to accept that he will never be you, but that being second best isn't such a bad thing!!