You know you dare not approach to join in. The subject of the good humor is filthy. During the day, as serious opinions are discussed, there is an opportunity to give the biblical view on issues of sin and righteousness or the purpose of life. But each time you speak, you have seen rejection of yourself with your views. Each testimony for truth makes you more unwelcome.
Christians are sensitive.
We want to be liked and accepted. It is our longing to become more intimate with fellow men. Some brutes witness with an attitude of 'I don't care what anyone thinks of me'. That is to be callous, not gracious. As God's grace quickens in us love for men, a sense of courtesy is heightened, a longing for gentleness and peace is increased.