If your comfortable with that and you trust him or her, I'd just be careful cause you know he/she might take a picture of it and share it but I'd only think that since me and my forever changing best friends would always try to make each other feel bad but I'm sure you guys aren't like that.
I recently came out to my best friend so I can tell you first hand that it feels great. At first he didn't take it well but he eventually came around and we're closer than ever. It all depends on how you feel about it too. Do you trust them fully? What's his/her stance on lgbt? Good luck!
Do whatever makes you the most comfortable. Best of luck, let us know how it goes! It's always scary, but the relief is much greater than any fear.
Do it in what ever way you feel most comfortable. The first few times i came out was over text as I couldn't bring myself to say it face to face but as I became more comfortable and confident I've managed to do it in person. I came out to my best friend via text after I had failed to say it to her face all evening after I had planned to and everything turned out great, we're closer than ever. I was terrified when I first came out but I wouldn't change it for the world - I am so much happier, relaxed and relieved. The weight I felt lift from my shoulders was immense. I would suggest that the first person you come out to is someone who will most likely support and accept you. The first person I came out to was a friend who had gone through a similar thing and it felt so much easier the second time knowing that I had support behind me. Good luck!!!! Xx
I would say call him/her if at all possible. The more personal, the better. Especially with a best friend.