Kindly refer to the following link(s):  

Non-Mahrams free mixing with make-believe relationships


But cousins are like brothers!


Family thinks I am extreme for not mixing with family members of the opposite gender


Why does Islam promote segregation among opposite genders?


Free Mixing, Attending Free Mixed Gatherings



Wedding with music & Free mixing, how to tell I can't attend, giving gifts before the function starts


Is free mixing in Restaurants, Airplanes etc same as free mixing in Classes?


Those who justify free mixing by Prophet's ﷺ marriage to Khadijah & who was Umm Sulaim?