If you fall in love with someone you shouldn't love at a bad timing, you will be the most confused one. Regardless of whether your relationship with your friends is good or bad, what you are suffering from is the guilty feeling caused by moral sense.

That said, love is not something that can be continued with reason forever. Depending on the situation, you may choose affection, but as time goes by, the painful feelings will likely grow day by day. In such a case, you would be happier to give up on these emotions.

Even if your friend's partner has feelings for you and approaches you, it cannot be said to be a happy thing for you, who values your friendship. Therefore, it would be best for you to give up on this emotion. It is okay to keep a little distance from your friends, but it's better for the two of you if your friends don't find out.