Infiltration

Here's the dilemma. I pretty much got offered a job (from a lady I worked with at my old job) to work at a gym as a PT. It's like a job just fell out of the sky! Crazy! But... there's a catch... It seems a bit ironic. This gym happens to be the same one that an ex-friend goes to. Imagine the awkwardness of working there and potentially running into her.... In some ways I feel that if I don't take this job because of that reason, I am throwing a way a gift - every rose has its thorn right? BUT I know that me living my life ... dipping my foot in the pond, simply being somehow associated with that person, could cause a wave in one form another... It's like I can't get away from it... it keeps coming back. It seems too much of a coincidence in life for this dilemma to take place. What should I do? If I don't take the job I'm letting the pettiness of the situation control my life - literally (job choices? really?) and if I do.... that's the mystery. At this point I'm leaning toward taking the job and not letting the fitness facility choices of people I'm on bad terms with deter me from a potentially great job experience... it's in the back of mind though - maybe I'm just worrying.