I wouldn't be embarrassed at all! I think its fun to talk to my mom about this sort of thing.
Personally, my kids are still 10yrs and younger, so I haven't had this happen to me yet. However, I am the type of mom that will be being very open and honest with my kids about their sexuality and helping them to understand sex and their bodies. My mom wasn't really there for me in that sense when I was going through "changes", so I want to make sure that I create that type of dialogue between my kids and I.
As far as when they get older, I wouldn't have any issues at all. My mom has a real sense of humor when it comes to this stuff. I was an independent rep for another company a while back, got my "demo kit" in a HUGE brown box and brought it over to my grandmas to show my mom and grandma. They laughed and were stunned when I pulled some of those toys out of the box! We joked about it and laughed. My grandma seen what was in the box and said "Welp, thats my cue!" and laughed as she walked outta the room.
It all depends on the type of relationships that you carry with your kids. If you're straight forward and open with them when they are younger, it won't seem like such an embarrassment. We're all adults. We don't talk about how it feels or what we do with it, we just talk about the toy itself or laugh at stuff we see and what not.