Oh they'll photoshop it. You'll be able to spot fakes by the pics they post and the way they talk, 9 times out of ten. What you need is a chat with webcam, you both ask each other to hold x amount of fingers or something.
For couples, check their dickpics to see if they are fake. Some wannabe's be posting both cut and uncut cocks claiming it's them... Most are really low effort tbh. Once spotted one where the cocks were fairly similar, down to the veins. But one had a outie and the other a inward bellybutton.