How do I ask my boyfriends SIL and BIL to stop being so self-centered but politely?

When we see our in-laws (BIL & SIL) they bombard us with their life's plans and problems. After a dinner with them we are drained. Not even a minute of the conversation is reverted back to us. How do I get them to see they are being impolite by bombarding us with all their problems every time we see them? Not to mention definitely crossing some personal boundaries when constantly asking for help - we have a life too we just don't whine about our lives to everyone! I want to say it without stirring up any conflicts.