Yes, it is clearly an inappropriate interest. Such a topic is private and should not be a subject of interest among people in this relationship. It violates the normal boundaries of friendship and marriage.
No, it is not a common expression at all. In normal English usage, we don't come across such a phrase. It seems rather strange and not part of the standard vocabulary or expressions.
You might also need to have an open conversation with your wife. Explain the situation to her without causing unnecessary misunderstandings. Maybe she can help handle this delicate situation. For instance, she could talk to her friend and make it clear that such behavior is not proper in the context of your relationship.
This situation might suggest that your girlfriend is very attracted to you physically. But it's important to look beyond just the physical aspect. If the relationship is only about this, it might not be sustainable. You need to build other aspects like mutual respect, understanding, and shared interests. Maybe start having deeper conversations to strengthen the emotional bond.
Well, here's one. There was a rooster on a small farm. This rooster was really proud. Every morning, it would wake up the whole farm with its loud crowing. It was so protective of the hens in the coop. Once, a fox came near, and the rooster bravely stood in front of the hens and flapped its wings furiously, scaring the fox away.
Well, 'drunk husband loves cock stories' is a rather puzzling statement. 'Drunk husband' is a common enough concept. But 'cock stories' is quite strange. It might be that in some sort of very specific context, like in a group of people with their own unique jargon, it could mean that the drunk man likes stories that are perhaps inappropriate or it could be a completely innocent misnomer for some other type of story. For example, it could be a play on words gone wrong and the real meaning was something like 'clock stories' where the drunk husband likes stories about clocks.
There is no obvious origin for such a strange phrase. If we assume 'cock' refers to a male chicken, it might have originated from an oral tradition in a rural area where roosters were important animals. The stories about their behavior, their role in the farm, etc. could be what a man learns to love. But this is all just speculation as the phrase as it stands is rather ungrammatical and unclear.
It could be that 'teenage' is related to a time period in the past when there were tales about a cockerel (cock) on the farm. Nanna loves these nostalgic stories from the speaker's teenage years.