The first part is really simple.  If you're paying for a dance, it's illegal.  The second part, are the Montreal police going to charge.  The answer is, not in the last 10 years while it's been illegal.  You don't have to touch; if you paid to get aroused, by the definition set by the Court of Appeal, it's prostitution.   
When Campus first started you could have a table dance, or go in the back.  Based on the current definition, both would be prostitution.    
And need I repeat, the decision of the Court of Appeal was in 2010, and it hasn't been applied since.