Is She or Isn't She... That Tis the Question

So one of my sisters, E, has been wondering if our friend L is cheating on her hubby. I say no, but I still wonder (unfortunatly for L so does her hubby). My sister comes to visit me at work today. I work in fashion, L works at a cosmetics counter in the same store. E and I talk for a bit then she says she is going to go say hi to L. When my shift is over, E and I head outside for a smoke. She proceeds to tell me about this guy who looks very similar to L's hubby (but different enough that she knew it wasn't) came over to the counter. Him and L hug and she kind of 'subtly' moves E along. This has totally piques E's curiousity. Hence why she mentioned it to me. If anyone would get to the bottom of it I would. Between flat out asking L, to subtle questions, or as a last resort asking L's friend W. Hehe, sneaky, but asking W won't work because W is having an affair and isn't a fan of L and I spending time together. REAAAAALLLLY want to know. Thanks E for perking up my interest too!