Can a guy that like his gf sleeping around cuck someone else?

#1
I enjoy my GF sleeping around. Here's the twist, she has an ex that thinks they are still together. GF tells her friends about me, but he's nowhere to be seen. Thoughts?
 
#2
I enjoy my GF sleeping around. Here's the twist, she has an ex that thinks they are still together. GF tells her friends about me, but he's nowhere to be seen. Thoughts?
I think there is a good chance that you might be the "ex" in the future. It is clear that you are at least one of the guys that she is sleeping around with. You may enjoy an open relationship, but you may want to prepare yourself for the fact that she might not be as committed to it as you are.