<human>: Two of my friends from university have been in a serious relationship for almost two years. My friend, i'll call him "Sam", has been texting me quite frequently about how his girlfriend "Becky" has been asking for a lot of space where they don't talk for days at a time and making strange statements when they DO talk such as "I think people can love two people at the same time".

From what Sam has described to me, it sounds like Becky wants to end the relationship and start dating other people. She has actually outright said "I think I want to start dating other people" to him. 

To complicate things a little more, "Becky" has a male friend who is also a mutual friend of ours, in which I have sensed a massive attraction between the two of them for a while now when I have been around them. They talk every day and go out by themselves for "walks" etc (without her boyfriend, Sam). This friend of Becky's has now openly admitted he has feelings for her which has deeply upset Sam.

I am pretty much certain that Becky and her friend have feelings for each other and most likely want to start dating. I know that I should not assume people's feelings but it is so damn obvious.

Sam is so blind to all of this and is in complete denial that Becky is not happy in their relationship. I find texting him very difficult because I am completely unsure of what to say. He is a very anxious person and I do try not to say anything that will upset him, but should I be the one to tell him what he is trying to avoid? Should I be blunt and honest or let time tell what happens with their relationship?

I want to be a good friend to both of them, but I am unsure of which route to take with this situation I have found myself tangled up into.

Help reddit!

Summarize the given text in a few sentences.
<bot>: Friend who is in denial about relationship with his SO coming to an end even though signs are pretty obvious. Texts me very frequently for advice. Unsure what to say...