My question now is that is it wise that I showed him the amount of Bitcoins I have accumulated before he developed interest?
You did well introducing your friend to bitcoin, but it was not a wise move to divulge the details of your current bitcoin balance even though you see the person as friend or family. We always need to be cautious when we tell people things, so we do not over speak and share the information that is not meant to be shared. You can be friends with someone and they are not friends with you, and also your relationship with someone may not remain the same forever, so always be cautious the information you divulge, sensitive information about yourself can be used to hurt you later.
That's right, introducing Bitcoin to friends, close people and even family is just sharing experiences and providing good basic knowledge so that they can know and understand Bitcoin so they can develop it themselves if they are interested.
However, you do not need to reveal your Bitcoin amount and details as it is very risky. Moreover, OP states that she hasn't been friends or known him for years, maybe he was a good friend at that time, but OP also has to consider whether the person he was then is still the same as he is now, and this must be taken into account.
And this is a beginner's mistake and who knows what the purpose is, if only to make them believe by showing ownership. In my opinion, it can't have any effect, it will actually make you cry if something undesirable happens.
And a good way in my opinion is, you become generous and change overall significantly so that it makes them wonder what made you change, and with this you can easily introduce Bitcoin because the proof is that you changed in appearance and also financially.