help my baby boy is a baby girl!?

So i adopted 2 kittens when they were 6 weeks old and i was told they were both males. didnt think much of it. fast foward 4 months later and 1 of them is acting like "she" is in heat! ive had a female before so i noticed it right away. i havent had them fixed yet cause i wasn't rushing since they were both males and housed inside. so now im crying cause i have to keep them separated until i get them fixed which they are best friends. what do you think??

"she" even looks wet

female right??