Lol, a most unusual thread. My mom gave me baths up until I was 20, but until then she didn't call it anything out of the ordinary.
Dude, that's sick, your mom touching your penis and thinking it was a doorbell and making that sound. Just plain sicko.
My mom usually referred to it as "boys'...you know...thing." I think she only mentioned it once or twice to my sister and I. Now my grandma's explanation was completely awesome. And it was only a couple years ago. She warned us that males can get "excited" sometimes. Out of amusement I feigned ignorance so she would explain more. And she told us what happens when our grandpa gets in bed with her..."his junk goes whoosh," imitated it with her finger (curled and then straightening out and pointing upward) and everything. Scarred. For. Life.
She always called it my "MacBeth"... True story, though, I was, I don't know, about 5 or 6 when the "You down with OPP" song came out. I would walk around trying to sing it, only I always said "I gotta go PP, yeah you know me!" and grab my crotch. My mom would get frustrated and say, "Why don't you go then?!?!"