Originally Posted by cherokeesam
You guys are reading Tony's line in the trailer about "protecting the only thing I care about" as meaning he wants to build Pepper a high-tech chastity belt or something. Instead, the answer is probably much simpler and more dramatic: it indicates that there'll come a point in their relationship in this movie where both Tony and Pepper will have to recognize that the only way for her to stay safe is for Tony to distance himself from her, and call their relationship quits.
Maybe the thing he is protecting is IronMan, the legacy he has created. Hopefully the film isn't just a story of Tony and Pepper.