I'm in my first relationship so I'm virtually new with anything beyond kissing. I wanted serious answers here since I'm not experienced at all. Are these following things safe:

1. My girlfriend is lying on her back, and I stick my penis (when hard) below her waist, you know like "in the spot". But we both are fully clothed wearing jeans or some sort of pants.

2. Me sucking on her boobs & her sucking on my penis

Also, what exactly makes a guy jizz?

I would appreciate any serious help, thanks