Can't do

"What's wrong, sonny?" asked the old timer sympathetically, coming over to the little kid who was sitting on the curb, crying his heart out. "I'm crying 'cause I can't do what the big boys do!" So the old man sat down and wept too.

Grandma's Peanuts

A guy goes to visit his grandmother and he brings his friends with him. While he's talking to his grandmother, his friend starts eating the peanuts on the coffee table, and finishes them off. As they're leaving, his friend says to his grandmother, "Thanks for the peanuts." She says, "Yeah, since I lost my dentures I can only suck the chocolate off 'em."

Infrequently

Bernie and Jane are an elderly couple who have decided to get married late in life. While they have not yet been intimate, Bernie thinks it would be a good idea to know how Jane feels about this. He asks her about her desires regarding frequency of sexual intimacy. Jane replies that she likes sex infrequently. Bernie, being ever the optimist says, "Is that one word or two?"