The more the merrier...BUT ONLY if YOU want the second bird for yourselves, and not for Mango...It's very simple: You have no idea if any bird that you bring home will even be able to be in the same room with Mango or vice versa, so often people who buy a bird as a "friend" for the bird they already have end up with two birds that hate each other, attack each other, can't be near each other, etc., and then you have two birds...And your time with Mango, which right now is quite plentiful apparently, gets split in half because you have to spend just as much time with the other bird...So you trying to get Mango a friend turns into a bad thing all the way around...And especially with a bird who has had you all to himself for over a year, they tend to become extremely jealous and territorial whenever a new bird is brought home.
So, if you are truly only wanting another bird as a "friend" for Mango and that's it, then NO, don't do it. If you want another bird for you and your husband to spend time with, then great, do it. But be prepared before-hand to have to house them separately, keep them in separate rooms, etc. just in case.
***Something a lot of people don't realize is that bird/parrots are "flock animals"...you have been Mango's "flock" for almost 2 years, he is happy and healthy. So he doesn't need "a friend" at all as long as you guys are spending that much time with him every day....just make sure you're aware that while your intent to "get him a friend" is very good, it may very well end-up actually taking time that you spend with Mango away from him and serving to do the exact opposite...or it may be fine and they'll love each other and get along..that's the point, you can't ever know, and that's why it has to be a new bird for YOU, not Mango...Mango is very happy with his current flock...