There are many such bars in Thailand. certainly a number of them in Pattaya. They cater for a wide circle of clients, particualrly wives in unsatisfactory relationships and with incapable or absent husbands.
My boyfriend's cousin was a mamasan in one such bar in 2nd road. He showed me photos of the line-up. Thee guys were stunning. There was no go-go and they remained fully-dressed. His bar was the subject of a local TV show but the guys weren't shown.
It was termed a karoake bar. Prices for drinks and "offs"were similar to those in lady/gay bars.