Most Helpful Guy
well you can use this opportunity to out a cheater, or just leave the situation altogether and not let it be your problem anymore.
Most Helpful Girl
I think there is a couple factors that need to be considered in these situation...
1. Is this person mutually exclusive with someone else?
* yes, we are just talking though (maybe hugs or kissing can be included in this) . No, don't contact her but stop communicate with him and tell him you know because it's kindof fun to watch them panic. 😂
*yes, we are talking and have things are sexual. Yes, contact her but be respectful about it. This should not be to get back at him because he's a horrible human being (I feel your pain and also want him to burn in hell) but rather because ladies need to stick together and if he's not practicing safe sex methods he is putting everyone involved at risk. If your motives (this is general not directed at the asker) are to get back it him. No. don't. It's not healthy for you. And it's not fair to loop her into your very methodical plot to destroy him.
2.) is this person not mutually exclusive someone but you find out they are seeing other women?
* this is going to hurt but you should not contact the other woman. If you aren't okay with that I would let him know. He might stop seeing them because he's interested in you. He might say no (or lie!) and at that point you should part ways.