Question about the physical aspect of relationships?

I have only ever been in (and currently am in) one serious long-term relationship. I think the physical part progressed naturally (hand holding, then kissing, then making out, etc…) Each step seemed so new and exciting but after we had progressed they lost some of the excitement. Which I think is natural. What I would like to know is how it works in a relationship where the couple has sex the first time they meet. Is there a period where they rediscover the smaller steps of affection? Are they as pleasurable?