One of the best ways I get a laugh is being around my kids. It cracks me up when they use an expression completely innocently--but you can so easily take it another way.
Yesterday Little Brother sat next to me during Mass. After Communion, which we receive under both species, he returned to his seat and whispered, "That wine really hit the spot!" I just stared at him, wondering how much of it he drank...and he continued, "I haven't had a drink all day!"
After that, there was no keeping my composure, regardless of the inappropriateness of giggling during prayer-after-Communion time.