I'm going to make sex jokes with my friends while in a relationship
Why would you do that?
I think sex jokes are funny.
You shouldn't joke about sex and your relationship with friends. It's really disrespectful to them and your partner.
I just want to be funny and I'm sure my partner doesn't mind as long as I don't say it in public.
I am glad that your partner doesn't care but they might later on if it affects how others see them. Your friends might disrespect your partner if they think it is funny. And you started by disrespecting your relationship.