My BF of about year is halfway across the world for Xmas with his family. We had a bit of a rough patch before he left, although we left things on a positive note. The thing is he's got really close to a (female) 2nd cousin who he didn't know well before. He keeps mentioning how great she is, and I've seen social media pics - she is absolutely stunning (a lot more beautiful than me tbh).
They've been spending one on one time together, including when drunk, and he's also been acting as a shoulder to cry on her during relationship troubles. I know it's ridiculous but I feel a bit threatened, and I keep getting insecure that maybe he has feelings for her or prefers her to me. I think I feel worse because his only friends back home are other men. AIBU in feeling this way?