Blackmailing??

Help! ! Ok so im 18 years old. I have an ex who i broke up with to be with someone else. Let's call him bob. So Bob is threatening to send my dad vids n pics of me nude/mastubating. He's 17. My parents don't know bout having relationships. I got permission to date this guy i left him for. Let's call him Jay. I'm trying to be happy with Jay n someone told Bob that i was hanging out with Jay at my house.

I keep quiet bout who I'm dating so idk how he found out.

I can't have my parents get involved i just got permission to date Jay.

If Bob sends the vids or pics. To my dad imma get grounded, phone taken, n possibly won't be able to be with Jay. What can i do??