Chris has always had a weird understanding of commitment in relationships. As soon as he is in or even near a relationship, his presumption is that it will last forever.
To be fair to him, it isn't just a one way street. He vows his own undying loyalty just as much or more as he expects it from the other person.
In a way, there is something a little sweet about these vows and this attitude. If my nine-year-old cousin wrote that type of vow to a girl in his class, I would think it was adorable and showed he was a good kid. I don't quite know how to feel about that attitude coming from Chris. It is naive and innocent in kind of a charming way, but there is a level of creepiness about it too.
What I can't figure out is whether that creepiness is inherant to this part of his attitude in particular or if the creepiness is just poor execution or bleeding in from other parts of Chris.