Resultados posibles:
acariciabas
-you were petting
Imperfecto para el sujeto del verbo acariciar.
acariciabas
-you were petting
Imperfecto para el sujeto vos del verbo acariciar.

acariciar

Eso no te preocupaba anoche cuando lo acariciabas.
You didn't mind it last night, when you ran your fingers through it.
Palabra del día
la víspera