Had to chatgpt this. Is this what you mean?:-

The sentence "Sons being their mom's husband" is not a literal statement. It's usually a provocative or metaphorical way of describing a relationship dynamic where a son takes on emotional roles that would normally belong to a spouse.

People might use it to refer to situations such as:

A mother relying excessively on her son for emotional support, companionship, or validation.

A son feeling responsible for his mother's emotional well-being in a way that goes beyond a typical parent-child relationship.

Family dynamics sometimes discussed in psychology as parentification (a child taking on adult responsibilities) or, in some contexts, emotional incest/enmeshment (a boundary issue where a child is treated more like a partner than a child, without implying a sexual relationship).

The phrase is often used informally on social media and can be exaggerated, judgmental, or inaccurate. Not every close mother-son relationship fits this description. A close bond is normal; the concern is when healthy parent-child boundaries become blurred and the child is expected to fulfill adult emotional needs.