Bestue
Kinda like bestie only a hella lot fantastical.
"Whats chillin', Bestue!?"
Bestus
a sarcastic way of saying someone is not very good at a given task
Man, he is the bestus basketball player ever!
Bestu
Boy and Girl who are best friend and have sex even though they are in a relationship with other. Similar to friends with benefits. The word gain popularity in the year 2017, May, after a long story was published in confession page.
I had a bf and he too had gf. But I had sex with my bestu. He gave me more pleasure than my BF. We are bestu.