Dreams of other half being unfaithful

I had a dream last week that my boyfriend slept with his ex behind my back.

Last night I had a dream that my boyfriend cheated on me with someone from his work. I literally woke up almost crying. I woke up and shook him saying "you cheated on me, why?!"

Like why do I keep having these dreams? What do they mean? Last nights dream is so vivid it's genuinely pissed me off. Anyone else have this 😩