Word to describe that only one side of the party is talking?

Question

Example sentences:

Susan didn't enjoy the date, because it was too __.

Mary's marriage has become __. She's the only one speaking.

Answer 1

"One-sided" is common usage and would work in both of your examples; however, its usage is broader than just about conversations -- though it is often used to modify 'conversation' (see many results for 'one-sided conversation' google search, or http://www.basicinstructions.net/basic-instructions/2009/4/29/how-to-end-a-one-sided-conversation.html).

If you wanted to avoid usage of one-sided, your options for a one-word solution might be limited or awkward. There are some idioms for what you describe, such as:

• She dominated the conversation
• He monopolized the conversation

You may also consider use of the word "monologue," which has the usage "a prolonged talk or discourse by a single speaker, especially one dominating or monopolizing a conversation" (http://www.dictionary.com/browse/monologue).

Answer 2

One could say that the conversation was lopsided:

Lopsided:

ADJECTIVE

1 With one side lower or smaller than the other.

‘a lopsided grin’

1.1 Disproportionately weighted in favor of one side over another.

‘a lopsided competition’

https://en.oxforddictionaries.com/definition/us/lopsided

If it suits, you might also explore concepts such as unbalanced or uneven.

Answer 3

Unilateral is another possibilty for your second example:

adjective

(of an action or decision) performed by or affecting only one person, group, or country involved in a situation, without the agreement of another or the others.

(from https://www.lexico.com/en/definition/unilateral)

It is simply a highfalutin way to say onesided, which was already given.

Answer 4

monologue:

A monologue is a speech delivered by one person, or a long one-sided conversation that makes you want to pull your hair out from boredom. The Greek root word monologos translates to “speaking alone,” and that's a monologue: one person doing all the talking.