Same here. I broke my collar bone riding in a group bcoz one of the other riders made a mistake. Having said this she was inexperienced and not used to riding with us. And this is the thing .. To ride in a group you must get to know them and trust them and this doesn't happen overnight. If your boyfriend is asking you to go out with him, he's not asking you to go out on a club ride. Just as you don't know how he rides, he doesn't know your capabilities either, and he's not expecting you to ride 3 inches of his wheel and vice versa. He just simply wants to go out for a ride with you, he's not asking you to join his club ride. Tell him how you feel and set the rules first (ie slowest rider sets the pace and it's a social ride) and then go with him, you'll be fine.