Muchos gracias .
Muchas, not muchos. Feminin.
For instance, if you want. To express the desire to have many penises in your mouth, you say: Quiero tener MUCHOS penes en mi boca.
Penis is consider masculin.
On the other hand, if you want to tell the spanish whore that you have many std's, you say: Tiengo MUCHAS enfermedades transmissibiles sexualmente. Because disease is consider feminin in spanish.