I took my other half for the first time earleir this year, I had the same concern, I wanted him to love it and want to go back. I started out with Disney in a more subtle way. We went to Universial and stayed onsite for the FOTL passes sohe didn't have to queue, he liked that. When we went to Disney the first day we did not go to the parks, but went to 'Ohana for a late dinner and I didn't tell him about wishes, just mentioned we might see some fireworks. Well, that blew him away!
The first part we did was MGM Stuidos and Fantasmic, which he also loved, and when wew went to the Magic kingdom I made sure I took him to the mid spot to look up at the castle and he was hooked. I took a slow introductio approach in case it was too much or too 'disney hardcore'.
It worked!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!