It takes two to tango: If two people were involved in a bad situation, both must be a little responsible.
Variety is the spice of life: You should try many different kinds of experiences, because trying different things keeps life interesting.
Every cloud has a silver lining: All ‘bad’ things come with some ‘good’ attached to them
People who live in glass houses shouldn’t throw stones: You should not criticize other people for having the same faults that you have.
Burn your bridges: To cutoff the way back to where you came from, making it impossible to retreat
Burning the midnight oil: Working late into the evening or through the night.
Water under the bridge: Something that belongs to the past and isn’t important or troubling any more.
Wear your heart on your sleeve: To display one’s feelings openly, rather than keep them private.
What goes around, comes around: Whatever you do in this life to other people, whether it is good or bad, the same will eventually return to you.
Two’s company, three’s a crowd: A way of asking a third person to leave because you want to be alone with someone.