Definitely a NSFW joke, but worth the tell, if you promise not to stare:

Little Johnny arrives at school, ready for English class. The teacher soon gets under way, and before long she announces to the class, “Today we are going to learn about multi-syllable words. Does anyone perhaps have an example of what I am talking about?”

Excitedly, Johhny waves his hand, “Me, teacher, me, me!”

With a sigh, the teacher asks, “Okay Johnny, what is your multi-syllable word then?”

Beaming, Johnny says, “Mas-tur-bate.”

Teacher smiles and patronisingly says, “Wow Johnny, that sure is a mouthful!”

To which Johnny quickly replies, “No teacher, you’re thinking of a blowjob…”