It's natural to have questions or concerns when you notice something like that, but it's essential not to jump to conclusions or make assumptions without proper communication. Men can have erections during sleep, and this is a normal physiological response known as "nocturnal penile tumescence" or "morning wood." It is not necessarily an indication of what he might be dreaming about.
During the rapid eye movement (REM) stage of sleep, which is when most dreaming occurs, men can experience erections due to increased blood flow to the genital area. These dreams may or may not be related to sexual content or other people.
It's important to have open and honest communication with your partner about your feelings and concerns. Instead of assuming the worst, consider discussing it with him calmly and without accusations. Share your observations and feelings, and ask him about his experience and whether there's anything he'd like to talk about.
Remember that dreams can be complex and sometimes random, and they don't always reflect conscious desires or intentions. Trust and communication are crucial in any relationship, and discussing your feelings openly can lead to a better understanding of each other and strengthen your connection.
If you find that your feelings of concern or insecurity persist, consider exploring these emotions together or individually with a professional therapist. They can help you navigate your emotions and improve communication within your relationship.