This is the one time where I’ll call this a boyfriend/girlfriend relationship. For most of the relationship, neither person felt involved in the same way that Riley and Buffy were involved in their relationship. This is understandable, seeing as Angel is a very old vampire, and Buffy’s a high school student. They didn’t have a lot of opportunities for moments like the last gif here.
I think it’s important to point out that they truly did love each other, but neither was fully mature enough to completely be with each other.