
First off, honesty is the best policy. Do NOT try to hide it from your girlfriend, regardless of how she would react. Secondly, if it’s going to make your girlfriend insecure or uncomfortable… why even go there? You can do something platonic with a female coworker, but being gym buddies crosses a line in my opinion, unless it’s something your gf is totally cool with. Would you rather have your girlfriend or your female gym buddy?