This place isn't all gay, but has a sizeable gay clientele, especially on the ground floor. I found this place by accident . . . I was walking by and noticed a large number of tables near the windows with attractive men. That aroused my suspicions and it turned out that yes, this place gets gayer as the night goes on. Gay guys (mostly in their 30s and 40s) tend to start showing up around 7pm on the ground floor and more show up as the night goes on.
That aside, the food was very good and the prices good too. Try the "Menu El Cid," which is only 15 pesos (US$5) and includes an appetizer, a meal and a dessert. The ground floor is more for a quick drink and a snack, while the upper level is more for dining.