Mine all looked the same until I realized I was doing it wrong haha. You've probably seen some videos or read some instructions already, but I did that and I still wasn't doing it right. Although you do need to be gentle, you need to make sure you are pressing down enough on the sides of the genitals or it will not pop out all the way, and if it doesn't pop out far enough, then you cannot tell the sex clearly. Originally I thought all mine were males, then I discovered I had a female, and just a couple days ago, I thought one of the males was a female because I didn't press enough and his tube only poked out halfway.
The way I tell is that a male will have a lip all the way around the hole, like a circle, although sometimes it can look like an oval, and when it's oval, it acutally looks like a little slit but it will have a lip all the way around still. With the girls, when it's pushed out all the way, you will not see a complete rim, but rather the slit goes all the way down through the anterior part, so there is no lip at the very back of the genitals. But you need to make sure you are pushing it out far enough so that if there is a lip/rim in the back, it will pop out. I hope that makes sense.
