No one with any training and experience will carry that way unless forced to by circumstances. Carry without a holster is an accident waiting to happen. The gun can shift position and be elsewhere when you need it. It can fall out should you slip, fall, get jostled, have to run, etc. you might find yourself sitting down somewhere anyway. Stuff happens. Holsters are cheap insurance. Get a good one and use it. The Remora holster ( Home of the Original Remora No Clip IWB Concealment Holster) is designed to be held in place with just the friction of your clothing. From all reports they do a fair job. I would at least use one of those.
Oh, and welcome to the forum!