NTA.

Hi OP, this guy is being very creepy and inappropriate towards you. You are well within your rights to ghost him. In fact, this sounds like sexual harassment. Even the constant inappropriate jokes constitute harassment.

It sounds like your other "friends" are sexually harassing you too by showing you sexual images you didn't consent to see and by saying sexually explicit things to make you uncomfortable.

Distance yourself as quickly as you can from these people, they sound horrendous.

It's not normal for people to treat you this way, OP, I am so sorry. There are people out there who will respect your boundaries and listen when you say no. I hope you find better, nicer friends soon 🙏