The arms and hands
Clenched fists and crossed arms could imply your partner is getting defensive about something. You should try to pay attention to this, especially if you are fighting about something or you’re asking your partner to do something.
But if your S.O.’s arms are lightly crossed or even folded across their stomach in a sitting position, then this means that your significant other is feeling safe and relaxed. If you notice them holding out their hands with their palms facing upward or even outward, they might be doing so because they are relaxed, willing to communicate, and very open.
If you notice your S.O. standing with their feet shoulder-width apart or standing up straight and having an open posture, they might try to demonstrate more confidence and power. On a similar note, if your partner stands with their hands on their hips, they must be feeling more confident.
If you notice them standing slumped down, legs crossed, or hands in their pockets, they probably feel tense, sad, or embarrassed about something.