Your forehead is so big your soulmate didn't even want you.
Large Forehead
Explanation
Explain Bear
Listen up, buttercup. This joke is saying someone's forehead is so ginormous that even their soulmate couldn't handle it. It's like saying your forehead is a deal-breaker in the love department. And let's be honest, with a forehead that big, you could probably land planes on it, which is why you're probably single.