Buzz up! Pregnant 17-year-old Bristol Palin and her 18-year-old boyfriend Levi Johnston displayed their commitment to each other at Wednesday's GOP convention. Johnston debuted a "Bristol" tattoo on his ring finger, while Bristol rocked what appeared to be an engagement ring. (McCain campaign officials have yet to identify the ring.) In a statement announcing that their daughter was five months pregnant, Sarah and Todd Palin noted that the teenage couple planned to wed. Levi flew to the convention in Minnesota from his Alaskan hometown on Wednesday. He was warmly greeted at the airport by Sen. John McCain. Levi's mother, Sherry Johnston, recently told the Associated Press that there had been no pressure put on her son to marry Bristol and that the two teens had made plans to wed before it was known she was pregnant.