I always tip but I come from the bar industry so I tend to over tip on meals and drinks and cabs - I always tip SPs I see but I don't think I've ever felt they expected it - even girls I repeated with. I usually have a 20 for the SP I see and give it to her after the call is done - the only time I would not tip is if something went horribly wrong - I have luckily only had good experiences with SP's in Toronto!