Verb - The action of a person or persons that jump into the middle of a conversation and start talking over everyone putting in thier two cents whether it was asked for ot not.
"So i was talking to Stevethe other day about his wife being pregnant right, and in jumps Marcy and John and they totally convojack me because they have had a kid recently. Those two seem to convojack me at every chance they get"
When you say congratulations 🎊 with a tinge of envy or disdain, but you feel the need to hide or supress it. By being petulant, you end up hiding it badly.