I haven't done carry-on, always checked my bags or bag that has my pumping tools. In that sense, no worries. Wouldn't know how it my go if it was in my carry-on, some questions could raise, but it's not an illegal tool (or adult toy) in most countries or states to my knowledge.
So, personally I wouldn't travel with [words=https://officialhydromaxpump.com/?uid=6&oid=2&affid=98 ]BM[/words] in the carry-on, but it isn't listed as a dangerous item, so in a way it's 50/50, you could be questioned and that might be embarrassing or not.