I think you should be prepared for the possibility of Bentley being jealous. It may not happen, but it could, especially if Bentley has been an "only" dog for a long time and has a strong bond with you.
I used to have 2 Cockers together many years ago. I got the second one when the first was almost 2 years old and they got on reasonably well right from the start. They would play together, lick out a yogurt pot together etc. but didn't like to share the same bed and would have the occasional small squabble.
I now have a 5 year old Cocker, William, who has been my constant companion and shadow for the last 5 years. My husband works abroad and I'm on my own a lot, so William has been an only dog with just me looking after him, not a family sharing him. He is a gentle, loving and usually placid dog.
I introduced a new puppy, Louis, into the household 3 months ago. William's first reaction was to sniff, growl, then ignore. He still ignores Louis most of the time but also tells him off by growling and knocking him over. William is very jealous of any attention that I give Louis and as I'm on my own I find it quite difficult to spend time just with William on his own. So William now gets a lot less attention than he did before and our relationship has suffered because of that. I feel guilty because although I'm enjoying having Louis, William's life has changed in ways that he doesn't understand and doesn't like
I think that eventually things will improve and William will be more accepting of Louis and less jealous. But I don't think they will ever be best friends.
I hope that Bentley doesn't have the same problems and gets on well with your new puppy straight away. There are plenty of other people on COL whose experience introducing a new puppy to an older dog has been better and easier than mine and I'm sure some of them will post on here.
Good luck with your puppy. What colour is he and does he have a name yet?
