4. Walk right in front of him on purpose.
For this approach, walk in front of your boyfriend in a really obvious way and judge his reaction and expression to see what kind of relationship he has with the woman he’s with. If he makes all kinds of excuses, doesn’t make any comment at all, or pretends the whole thing never happened, he’s probably hiding something from you. The main benefit of this approach is that making a judgement based on your boyfriend’s reaction puts you at an advantage.