you talk to the pokemon that is folowing you than it will tell you wether it is happy or not
You can't but if you check the Pokemon Music Channel (on Wednesdays ONLY) you might find some Pokemon from the Hoenn Region...
The same place you can get a life, loser.
Pearl and Platinum
With the happiness checker you get in the Pokemon center in etera city.
You can check a Pokemon's happiness at a game's happiness checker. Where the person is located depends on the game you are playing.
A certain person in verdanturf town will let you know your pokemon's happiness.
Go to Vendanturf town Talk to the lady in the house beside "Wanda's House" Note: the Pokemon that you want to check it's happiness must be in front of the line.
get the Poke tech App Poke happyness
With the happiness checker you get in the Pokemon center in etera city.
I know that togetic does....you should check serebii
Press start go right to happiness love , smart , cool .
you can check a pokemons happiness in Diamond/pearl by the use of a poketch app, in previous games you could only know in the happiness was maxed by obtain a ribbon from a certain character depending on the game.