Complex sentence: Angel and Buffy talk, Buffy tells him how hard it was for her to see Faith with him, Angel tells her it was not about her (Buffy), it was about saving Faith's soul.
Split into simpler sentences: Angel and Buffy talk about how hard it was for her to see Faith with him. Angel counters that and tells her it was not about her (Buffy), it was about saving Faith's soul.