Two people that were born on the same day. They do not have to be blood relatives.
Paul and Scott were both born on June 30, therefore they are birthday brothers.
When a nice person has many attractive friends of the opposite sex, but all view him/her in a brotherly light, and have no romantic feels for him/her.
Although James had many female friends, he could not get any to date him because of his unfortunate case of brother syndrome.
an annoying family member that cares about you so much that he ruins your life
I hate my brother
Two or more guys that have had sex with the same girl
After you do her, we'll be hole brothers.
Two guys (usually already named Moritz) that are hot as fuck
Girl 1: ouuh look at these two. They are soooo hot.
Girl 2: they are probably Moritz Brothers
Two men who have had their genitalia touched by the same masseuse.
A: She gave you a table shower after your massage? Me too!
B: That makes us junk brothers.
This term refers to two men who have had sex, and both ejaculated, into the same woman within a 24 hour period.
Purists of the word would add that the woman must not have showered or thoroughly cleaned her vagina between sex with the men.
Yesterday morning, Chalyse had morning sex with Asher and later that day, slept with Adam. I wonder if they know that they're slushy brothers.