Saga, I would say my knowledge extends well into expert territory.
After all, he can’t die from hypothermia because he’s already dead. If your guy is the star of the football team in a big way and his coach has said he's "the best we've seen in years", he’s totally a vampire. That’s weird, but understandable because he’s a million years old and, after all, age is a touchy subject. He’s not trying to keep up his bad boy reputation, he’s trying not to blow his cover. Maybe don't turn your read receipts on when you're off hunting? The guy isn’t even the slightest bit clumsy—not fair and not plausible. Stay with a soulless monster because honestly that’s hot and you don’t care what anyone says, was a masterpiece.
However, if there’s something freaky going on, you need to stare deeply into your boyfriend's eyes as often as possible and take note.
Now the specifics of vampirism tend to get tossed around a bit between movies and TV shows. Ladies never forget, vampire boyfriend or not, make sure you're the one doing the most slaying in your relationships.
After Caroline is turned in a vampire, he notices a major change in her and believes she's avoiding him, but he admits that he loves her.
She drinks his blood when he cuts himself and she compels him to forget that he saw her face change and he later breaks up with her, thinking she has jealousy issues.
The former romantic relationship between the vampire, Caroline Forbes, and the human, Matt Donovan.