Am I gay because I do this?

No No No you do not need to try it with a guy and decide.. that is selfish and immature. The reason you are feeling this is not only because you are horny but you are curious. This is referred to as “bi-curious”. Many females are like this because they are growing up, they like to know what this and that feels like, what is it like for males to get all the fun from females. It does not mean that you are bisexual or a lesbian. Your friend too is “curious”, however I do not think it is such a good idea to carry on doing it to each other because it can ruin friendships. I remember I used to do it when I was younger with another girl. I was 13. As it happens I turned out “open minded”. This is just basically straight with open views on other things. I can kiss or get into bed with a female and mean absoloutely nothing but with a male, it would mean something. I would even do it for fun. I am 17 this month and I know that it will be something that carries on into my 20’s probably because that is the growing up stages. Experimenting new things, meeting new people. Same as you.