What Kunti went through was Niyoga. This is described when she conceives Karna, when she asks Suryadeva how she'll ever get married if she loses her virginity to him (implying that intercourse takes place). Suryadeva then assures her she'll regain her virginity after she gives birth to Karna. It probably wasn't the same type of intercourse as human intercourse, but something definitely happened lol.
No serial has shown this till now because apparently, it's a touchy subject in our culture. 😆