This one guy on Facebook keeps telling me “my girlfriend doesn't like this” when I post certain pictures of myself. What the hell??

His gf doesn't like certain pics you post of yourself? Is she one of your fb friends also? Does he like or comment on these certain pics? It seems strange to me that she would have enough access to his feed for your pics to be bothering her enough to make an issue about them.

I think it's something else. I think he's probing you with matters of fact type complements so you wont think he's a dog for flirting with you while he's in an apparently committed relationship.

With this approach, he gets to be in the goodguy position the whole time, even if it leads to a full on love triangle. I'm not making any judgements about any of it. That's just a quick scenario i came up with when i pondered the given data.