interject (someone or something) into (something)
To introduce someone or something into a particular situation, often in a way that is meddlesome or unwelcome. Please don't interject your thoughts into this meeting, OK? You're just supposed to be observing. Please stop interjecting Mom and Dad into every little crisis in my life—I want to prove that I'm OK on my own!
interject someone into something
to force someone into something, usually into someone else's business. I am going to have to interject Fred into this matter before it gets out of hand. I hate to interject myself into your affairs, but I have something to say.
interject something into something
to volunteer information or a comment into a conversation. We can always count on Liz to interject something sensible into our discussions. At last, something sensible has been interjected into our discussions.