After three meetings with her, he told me that if I broke up with her, he and his girlfriend would still maintain contact with her, even though I hadn't mentioned breaking up. This, combined with flirty comments and actions between him and my girlfriend, raised concerns. Comments like “I’m the only one who flirts in this room” while looking at her, and her reaction being getting shy and starting to play with her hair.
Fast forward two years, and during a recent visit to his place, he made her cook while they’re laughing and giggling while cooking together. When the food was done my friend asked her to tighten the table leg (you have to rotate the leg), he then asked her in a flirty tone “is it tight?” And she responded “I would say it is tight”, - all this was done with a flirty undertone. When I expressed my feelings to my girlfriend, she denied any issue.