Lark around
Definition 1 of 1
Pro Tip 1/3Casual Context
Use 'lark around' in relaxed, informal situations, not in serious or formal contexts. 
At the family reunion, the cousins were larking around the whole time.
Pro Tip 2/3Positive Vibe
'Lark around' has a positive connotation, suggesting fun and happiness, not negativity. 
After the exams, we went to lark around at the arcade to blow off steam.
Pro Tip 3/3Group Activity
Often implies a group activity, with multiple people engaging in playful behavior together. 
The teammates larked around with the trophy, celebrating their victory.