well, I dont know you've resisted as it is. I was checking out some parrotlets just today at the store, but whats stopping me is the empty bank account and small apartment.
Honestly, if you feel like you have the love for all three, I'd say take him home. I wouldnt worry too much about your budgies because as long as you show them all the love they need, then they will adjust, in my opinion at least. Papi was an only bird for a while and now theres 5 all together, and everyone has adjusted. The main condiseration is you, if you feel like you chave the love and time to give all of them, and of course the money to support them, I see no reason why you shouldnt have a new friend.
Now I want to see pictures of the guy in his new home....
