Young girls sucking to please guys and keep them around. Nipples are successful and attract males. Everyone wants not only to fuck her pussy, but to give her in the mouth and cum after that. It's a pleasant sight - the partner's lips smeared with cum, the drops dripping from the end on her tongue, her breasts smelling of sex. For a man, this picture is the height of bliss. With that, the girl is down, expressing submission and acknowledging his power over her.
I think the pretty redheaded girl was trying so hard to return the favor, that she overpaid it so frantically and selflessly performed the cunny, especially since the comfortable conditions of a luxury cab allowed to do it perfectly