yes, it's because of their age difference. did the friendship level have all hearts after you connected them? as soon as they are able to mate they will.
you can pause it, or if you saved the tab that you pull out to activate the tama, then you can slide that back in; or you can take out the batteries (WARNING- these two methods will erase all of your saved information and you will have to start all over again)
the entama will not come out in the U.S. Later on, a version similar to the entama might come out...but no one has given any information out regarding that.
you should also try ebay.com
i think you gave him the love potion. it looks like honey. you give it to your tama when it can connect (as an adult) with another tama of a different sex.