Yeah it's bad. It means one or more of the following
1. She's a prude who looks down on a couple having some fun. Or
2. She's single and envious. Or
3. She has a bf or is secretly hooking up on the side. She feels all high and mighty and "superior" to this couple that is in their honeymoon-ish "fool around in public" phase. She feels like she is "better" than them because her fooling around is more private. Or
4. She's really old lol. (See signature thread below.)
My guess is #3