My boy is the same way; he loves getting cuddles and if he’s feeling like he’s had enough he either gives a little warning bonk with no claws out or just gets up and walks away.
Spoiler: No, it only makes a proper PRPRPRPR sound when done on skin without too much hair, so try your partner's belly when they fall asleep. It will will not work on a cat though. Source: I tried it on my cat, it did not make the sound. Then I tried it on the (now ex) gf and the sound was beautiful.
Sometimes.
If we're playing or she's clearly agitated, I wouldn't, because I know she'll get defensive and I'll get hurt. But if we're cuddly or she's sleepy, then yeah, I've been known to creep up to/pick up the cat and blow a raspberry in that belly floof. Most I get then is a light paw tap on my head telling me to stahp lol
I have 4 cats and I do this with 3 of them. They usually give you a befuddled look. The 4th one is just difficult to pick up in general, do it's never really an option.