The most close words you can find to the meaning of piropo in english, are pickup lines. Piropos are compliments and flattery people say to show interest on someone they want to hook up with, and there can be chessy, respectful and /or irrespectful piropos.
Mi mejor amiga siempre recibe piropos cuando salimos a pasear / My best friend always receives flattery comments when we hang out.
Learn spanish and other languages online talking native speaking teachers.
I hope you have learned something new, about the spanish that real Mexicans talk on their everyday life.
If you want to improve your Spanish, I also give tutoring lessons on skype using this page that host many teachers from all over the world, and while I don’t really do grammar, I can help with conversation and doubts about the language. Also, if you are interested in any language besides spanish, there are teachers and tutors for any language there.