This phrase is very difficult to interpret without more context. 'Cock' could refer to a rooster perhaps in a very strange context related to a'spooning story' which might be about people lying closely together like spoons. But it's all very ambiguous.
If we consider 'it slipped into mom story', it could be that there was a certain object or concept that got incorporated into a story centered around mom by accident or without much thought. Let's say a story was being told about mom's cooking, and suddenly a story about a kitchen gadget that she used once'slipped into' the cooking story. It might have been added because it was related in some way, like it helped her cook better, or it could have been just a random association that the storyteller made while talking.
It could mean a story where a wife made a mistake or had a slip - up. Maybe she accidentally revealed a secret, or made an error in judgment in a particular situation.
I remember when my little cousin came to stay over. We spooned while watching a movie. But he was so wiggly. He kept changing positions and at one point he accidentally elbowed me in the ribs. We both burst out laughing.
Once, my friend and her cat were spooning. The cat was so tiny and curled up against her. Every time she moved a bit, the cat would adjust itself and made these really cute meowing sounds as if protesting the disturbance of the perfect spooning position. It was hilarious.
Here's an example. A wife was chatting with her neighbor and slipped up by revealing some personal financial problems her family was having. Her husband had wanted to keep those issues private. As a result, there was some tension between the husband and wife as he was disappointed that she had let that information out. This kind of story shows how a wife's slip - up can have consequences on relationships and family dynamics.
Well, perhaps it refers to an object or an event. Say, a small memory or an item that unexpectedly found its way into the story about his wife while he was telling it. It might be something like a little joke that he didn't plan on saying but just came out as part of the story.
Well, if Dick accidently slipped in such a situation, he might face immediate embarrassment. People around him could be shocked or uncomfortable. He might also get a reputation for being associated with inappropriate content, even if it was an accident.