Straighten the fuck up.
1. To stand up straight.

2. To refrain from certain forbidden activities.

3. To act in a more compassionate and caring manner.

4. To refrain from illegal activity.

5. To steer clear of droolies.
1. Stop slouching, please straighten the fuck up.

2. Stop smacking you gum, straighten the fuck up.

3. Stop being disrespect, straighten the fuck up.

4. Stop speeding, straighten the fuck up.

5. Stop sleeping around, straighten the fuck up.