I agree with the others be professional, treat her as what job she's at, don't mention anything about her other job and tip well. You wouldn't want her seeing you at your job in front of your co workers and be like "oh while Im here I wanted to confirm your appointment this week to get pegged by me and my 10 inch strapon"....unless she's coming to your job to do that :lol:
When first started hobby back in the day, I ran into an even more awkward situation but stayed professional. Ran into a SP who the earlier in the week rode the living daylights out of me, walked into my work place with a ring on her finger and the guy who was to be her husband to do a tour and possibly book their wedding ceremony there. I acted as we just met and conducted everything professionally like any other client. They never booked there, she said the decor and layout was too odd. Saw her a few weeks later. Her man was in school and she was supporting him. He never knew, she told him something else about the money. I have nothing but respect for that lady and hopes she's happily married.