For dearest
John 5 things Buffy would warn Cordelia about Angel if their relationship had continued
1. He snores, no really he does. Like a foghorn. You wouldn't think it to look at him mister-I-sneak-around-a lot but he does and Buffy can remember nights where she spent them staring at Angel as he made those kind of noises. He was so quiet during the day but at night, whole different matter.
2. If you do sleep with him, be really really bad so Angel keeps his soul but still don't be so bad that neither of you feels it. If you catch her drift?
3. He'll brood all night if you let him. He'll find himself a nice comfortable seat and just sit there, brooding and sulking. Most of the time, he will spend his brooding moments regretting his past. A big no no so be sure to distract him.
4. He's got some psychotic exes which she would suggest steering well clear of, Cordelia doesn't have super slayer strength after all. Buffy knows that Cordelia wouldn't like Darla when she's angry.
5. The whole 'he's got a destiny' speel, bound to bite you in the ass sooner or later. Buffy always hoped for later and she does the same for Cordelia even if she's boning her ex. She suggests treading carefully, keep Angel honest and just hang on for the ride.